What is responsible for pain in the human body. Pain: causes and treatments
Pain is an important adaptive reaction of the body, which has the value of an alarm signal.
However, when the pain becomes chronic, it loses its physiological significance and can be considered pathological.
Pain is an integrative function of the body, mobilizing various functional systems to protect against the impact of a damaging factor. It is manifested by vegetosomatic reactions and is characterized by certain psycho-emotional changes.
The term "pain" has several definitions:
- this is a kind of psycho-physiological state that occurs as a result of exposure to super-strong or destructive stimuli that cause organic or functional disorders in the body;
- in a narrower sense, pain (dolor) is a subjective painful sensation that occurs as a result of exposure to these superstrong stimuli;
Pain is a physiological phenomenon that informs us about harmful effects damaging or representing a potential hazard to the body.
Thus, pain is both a warning and a protective reaction.
The International Association for the Study of Pain defines pain as follows (Merskey and Bogduk, 1994):
Pain is an unpleasant sensation and emotional experience associated with actual and potential tissue damage or a condition described in terms of such damage.
The phenomenon of pain is not limited to organic or functional disorders in the place of its localization, pain also affects the activity of the organism as an individual. Over the years, researchers have described an incalculable number of adverse physiological and psychological consequences not relieved pain.
The physiological consequences of untreated pain in any location can include everything from impaired function gastrointestinal tract and respiratory system and ending with an increase in metabolic processes, an increase in the growth of tumors and metastases, a decrease in immunity and a prolongation of the healing time, insomnia, an increase in blood clotting, loss of appetite and a decrease in working capacity.
The psychological consequences of pain can manifest as anger, irritability, feelings of fear and anxiety, resentment, discouragement, despondency, depression, solitude, loss of interest in life, reduced ability to perform family responsibilities, decreased sexual activity which leads to family conflicts and even requests for euthanasia.
Psychological and emotional effects often influence the subjective reaction of the patient, exaggeration or underestimation of the significance of pain.
In addition, the degree of self-control of pain and disease by the patient, the degree of psychosocial isolation, the quality of social support and, finally, the patient's knowledge of the causes of pain and its consequences can play a certain role in the severity of the psychological consequences of pain.
The doctor almost always has to deal with the developed manifestations of pain-emotions and pain behavior. This means that the effectiveness of diagnosis and treatment is determined not only by the ability to identify etiopathogenetic mechanisms somatic condition manifested or accompanied by pain, but also by the ability to see limitations behind these manifestations habitual life patient.
To study the causes and pathogenesis of pain and pain syndromes dedicated significant amount works, including monographs.
As a scientific phenomenon, pain has been studied for more than a hundred years.
Distinguish between physiological and pathological pain.
Physiological pain occurs at the moment of perception of sensations by pain receptors, it is characterized by a short duration and is directly dependent on the strength and duration of the damaging factor. Behavioral reaction at the same time interrupts the connection with the source of damage.
Pathological pain can occur both in receptors and in nerve fibers; it is associated with prolonged healing and is more destructive due to the potential threat of disruption of normal psychological and social existence individual; behavioral reaction in this case - the appearance of anxiety, depression, depression, which aggravates somatic pathology. Examples of pathological pain: pain in the focus of inflammation, neuropathic pain, deafferentation pain, central pain.
Each type of pathological pain has clinical features, which allow to recognize its causes, mechanisms and localization.
Types of pain
There are two types of pain.First type - sharp pain caused by tissue damage that decreases as it heals. Acute pain has a sudden onset, short duration, clear localization, appears when exposed to intense mechanical, thermal or chemical factor. It can be caused by infection, injury, or surgery, lasts for hours or days, and is often accompanied by symptoms such as palpitations, sweating, paleness, and insomnia.
Acute pain (or nociceptive) is pain that is associated with the activation of nociceptors after tissue damage, corresponds to the degree of tissue damage and the duration of the damaging factors, and then completely regresses after healing.
Second type- chronic pain develops as a result of damage or inflammation of the tissue or nerve fiber, it persists or recurs for months or even years after healing, does not have a protective function and causes suffering to the patient, it is not accompanied by signs characteristic of acute pain.
Unbearable chronic pain has a negative impact on the psychological, social and spiritual life of a person.
With continuous stimulation of pain receptors, their sensitivity threshold decreases over time, and non-painful impulses also begin to cause pain. Researchers associate the development of chronic pain with untreated acute pain, emphasizing the need for adequate treatment.
Untreated pain subsequently leads not only to a material burden on the patient and his family, but also entails huge costs for society and the health care system, including longer hospital stays, reduced ability to work, multiple visits to outpatient clinics (polyclinics) and points emergency care. Chronic pain is the most common common cause of long-term partial or total disability.
There are several classifications of pain, see one of them in Table. one.
Table 1. Pathophysiological classification chronic pain
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1. Arthropathy ( rheumatoid arthritis, osteoarthritis, gout, post-traumatic arthropathy, mechanical cervical and spinal syndromes) 1. Postherpetic neuralgia Mixed or indeterminate pathophysiology 1. Chronic recurring headaches (with increasing blood pressure migraine, mixed headaches) |
Pain classification
A pathogenetic classification of pain has been proposed (Limansky, 1986), where it is divided into somatic, visceral, neuropathic, and mixed.Somatic pain occurs when the skin of the body is damaged or stimulated, as well as when deeper structures are damaged - muscles, joints and bones. Bone metastases and surgical interventions are common causes somatic pain in patients with tumors. Somatic pain is usually constant and fairly well-defined; it is described as pain throbbing, gnawing, etc.
Visceral pain
Visceral pain is caused by stretching, constriction, inflammation, or other irritations of the internal organs.It is described as deep, constrictive, generalized and may radiate into the skin. Visceral pain, as a rule, is constant, it is difficult for the patient to establish its localization. Neuropathic (or deafferentation) pain occurs when nerves are damaged or irritated.
It can be constant or intermittent, sometimes shooting, and is usually described as sharp, stabbing, cutting, burning, or unpleasant. In general, neuropathic pain is more severe than other types of pain and is more difficult to treat.
Clinically pain
Clinically, pain can be classified in the following way: nocigenic, neurogenic, psychogenic.This classification may be useful for initial therapy, however, in the future, such a division is not possible due to the close combination of these pains.
nocigenic pain
Nocigenic pain occurs when skin nociceptors, deep tissue nociceptors, or internal organs are irritated. The impulses appearing in this case follow the classical anatomical pathways, reaching the highest divisions nervous system, are displayed by consciousness and form a sensation of pain.Pain due to damage to internal organs is a consequence rapid reduction, spasm, or stretching of smooth muscles, since smooth muscles themselves are insensitive to heat, cold, or dissection.
Pain from internal organs sympathetic innervation, can be felt in certain areas on the surface of the body (Zakharyin-Ged zones) - this is reflected pain. The most famous examples of such pain are pain in the right shoulder and right side neck with gallbladder disease, pain in the lower back with disease Bladder and, finally, pain in the left arm and left side of the chest in heart disease. The neuroanatomical basis of this phenomenon is not well understood.
A possible explanation is that the segmental innervation of the internal organs is the same as that of the distant areas of the body surface, but this does not explain the reasons for the reflection of pain from the organ to the body surface.
The nocigenic type of pain is therapeutically sensitive to morphine and other narcotic analgesics.
neurogenic pain
This type of pain can be defined as pain due to damage to the peripheral or central nervous system and not due to irritation of nociceptors.Neurogenic pain has many clinical forms.
These include some lesions of the peripheral nervous system, such as postherpetic neuralgia, diabetic neuropathy, incomplete damage to the peripheral nerve, especially the median and ulnar (reflex sympathetic dystrophy), detachment of the branches of the brachial plexus.
Neurogenic pain due to damage to the central nervous system is usually due to a cerebrovascular accident - this is known by the classical name of the "thalamic syndrome", although studies (Bowsher et al., 1984) show that in most cases the lesions are located in other areas than the thalamus.
Many pains are mixed and are clinically manifested by nocigenic and neurogenic elements. For example, tumors cause both tissue damage and nerve compression; in diabetes, nocigenic pain occurs due to a lesion peripheral vessels, and neurogenic - due to neuropathy; with hernias intervertebral disc, compressing nerve root, the pain syndrome includes a burning and shooting neurogenic element.
Psychogenic pain
The assertion that pain can be exclusively psychogenic in origin is debatable. It is widely known that the patient's personality shapes the sensation of pain.It is reinforced at hysterical personalities, and more accurately reflects reality in non-hysteroid patients. It is known that people of different ethnic groups differ in their perception of postoperative pain.
Patients of European descent report less intense pain than American blacks or Hispanics. They also have low pain intensity compared to Asians, although these differences are not very significant (Fauucett et al., 1994). Some people are more resistant to developing neurogenic pain. Since this trend has the aforementioned ethnic and cultural characteristics, it seems to be innate. Therefore, the prospects for research aimed at finding the localization and isolation of the "pain gene" are so tempting (Rappaport, 1996).
Any chronic disease or ailment accompanied by pain affects the emotions and behavior of the individual.
Pain often leads to anxiety and tension, which themselves increase the perception of pain. This explains the importance of psychotherapy in pain control. biological Feedback, relaxation training, behavioral therapy, and hypnosis used as a psychological intervention are found to be useful in some stubborn, treatment-refractory cases (Bonica, 1990, Wall and Melzack, 1994, Hart and Alden, 1994).
Treatment is effective if it takes into account the psychological and other systems ( environment, psychophysiology, behavioral response) that potentially affect pain perception(Cameron, 1982).
The discussion of the psychological factor of chronic pain is based on the theory of psychoanalysis, from behavioral, cognitive and psychophysiological positions (Gamsa, 1994).
G.I. Lysenko, V.I. Tkachenko
This is the first of the symptoms described by the doctors of ancient Greece and Rome - signs of inflammatory damage. Pain is what signals us about some kind of trouble that occurs inside the body or about the action of some destructive and irritating factor from the outside.
Pain, according to the well-known Russian physiologist P. Anokhin, is designed to mobilize various functional systems of the body to protect it from the effects of harmful factors. Pain includes such components as sensation, somatic (bodily), vegetative and behavioral reactions, consciousness, memory, emotions and motivations. Thus, pain is a unifying integrative function of an integral living organism. In this case, the human body. For living organisms, even without signs of higher nervous activity may experience pain.
There are facts of changes in electrical potentials in plants, which were recorded when their parts were damaged, as well as the same electrical reactions when researchers inflicted injury on neighboring plants. Thus, the plants responded to damage caused to them or to neighboring plants. Only pain has such a peculiar equivalent. Here's something interesting, one might say generic property all biological organisms.
Types of pain - physiological (acute) and pathological (chronic).
Pain happens physiological (acute) and pathological (chronic).acute pain
According to the figurative expression of Academician I.P. Pavlov, is the most important evolutionary acquisition, and is required to protect against the effects of destructive factors. The meaning of physiological pain is to reject everything that threatens life process, violates the balance of the body with the internal and external environment.chronic pain
This phenomenon is somewhat more complex, which is formed as a result of pathological processes existing in the body for a long time. These processes can be both congenital and acquired during life. Acquired pathological processes include the following - the long existence of foci of inflammation, which have various causes, all kinds of neoplasms (benign and malignant), traumatic injuries, surgical interventions, outcomes inflammatory processes(for example, the formation of adhesions between organs, a change in the properties of the tissues that make up their composition). Congenital pathological processes include the following - various anomalies in the location of internal organs (for example, the location of the heart outside the chest), congenital anomalies development (for example, congenital intestinal diverticulum and others). Thus, a long-term focus of damage leads to permanent and minor damage to body structures, which also constantly creates pain impulses about damage to these body structures affected by a chronic pathological process.Since these injuries are minimal, the pain impulses are rather weak, and the pain becomes constant, chronic and accompanies a person everywhere and almost around the clock. The pain becomes habitual, but does not disappear anywhere and remains a source of long-term irritating effects. A pain syndrome that exists in a person for six or more months leads to significant changes in the human body. There is a violation of the leading mechanisms of regulation essential functions human body, disorganization of behavior and psyche. The social, family and personal adaptation of this particular individual suffers.
How common is chronic pain?
According to research World Organization Health (WHO), every fifth inhabitant of the planet suffers from chronic pain caused by all sorts of pathological conditions associated with diseases various bodies and body systems. This means that at least 20% of people suffer from chronic pain. varying degrees expression, different intensity and duration.
What is pain and how does it occur? Department of the nervous system responsible for the transmission of pain sensitivity, substances that cause and maintain pain.
The sensation of pain is a complex physiological process, including peripheral and central mechanisms, and has an emotional, mental, and often vegetative coloring. The mechanisms of the pain phenomenon have not been fully disclosed to date, despite numerous scientific studies that continue up to the present time. However, let us consider the main stages and mechanisms of pain perception.Nerve cells that transmit pain signal, types of nerve fibers.
The very first stage of pain perception is the impact on pain receptors ( nociceptors). These pain receptors are located in all internal organs, bones, ligaments, in the skin, on the mucous membranes of various organs in contact with the external environment (for example, on the intestinal mucosa, nose, throat, etc.). To date, there are two main types of pain receptors: the first are free nerve endings, the irritation of which causes a feeling of dull, diffuse pain, and the second are complex pain receptors, the excitation of which causes a feeling of acute and localized pain. That is, the nature of pain sensations directly depends on which pain receptors perceived the irritating effect. Regarding specific agents that can irritate pain receptors, it can be said that they include various biologically active substances (BAS) formed in pathological foci (the so-called algogenic substances). These substances include various chemical compounds - these are biogenic amines, and products of inflammation and cell decay, and products of local immune reactions. All these substances, completely different in chemical structure, are capable of irritating pain receptors of various localization.
Prostaglandins are substances that support the body's inflammatory response.
However, there are a number of chemical compounds involved in biochemical reactions, which themselves cannot directly affect pain receptors, but enhance the effects of substances that cause inflammation. The class of these substances, for example, includes prostaglandins. Prostaglandins are formed from special substances - phospholipids, which form the basis cell membrane. This process proceeds as follows: a certain pathological agent (for example, enzymes form prostaglandins and leukotrienes. Prostaglandins and leukotrienes are generally called eicosanoids and play an important role in the development of the inflammatory response. The role of prostaglandins in the formation of pain in endometriosis, premenstrual syndrome, as well as painful menstruation syndrome (algodysmenorrhea) has been proven.So, we have considered the first stage of formation pain sensation– impact on special pain receptors. Consider what happens next, how a person feels pain of a certain localization and nature. To understand this process, it is necessary to familiarize yourself with the pathways.
How does the pain signal get to the brain? Pain receptor, peripheral nerve, spinal cord, thalamus - more about them.
Bioelectric pain signal formed in the pain receptor, along several types of nerve conductors (peripheral nerves), bypassing the intraorgan and intracavitary ganglions, heading towards spinal nerve ganglia (knots) located next to the spinal cord. These nerve ganglia accompany each vertebra from the cervical to some of the lumbar. Thus, a chain of nerve ganglia is formed, running to the right and left along the spinal column. Each nerve ganglion is connected to the corresponding area (segment) of the spinal cord. The further path of the pain impulse from the spinal nerve ganglia is sent to the spinal cord, which is directly connected to the nerve fibers. 
In fact, the dorsal could is heterogeneous structure- white and gray matter are secreted in it (as in the brain). If the spinal cord is examined in cross section, then the gray matter will look like the wings of a butterfly, and the white will surround it from all sides, forming the rounded outlines of the boundaries of the spinal cord. So here it is rear end these butterfly wings are called the posterior horns of the spinal cord. They carry nerve impulses to the brain. The front horns, logically, should be located in front of the wings - this is how it happens. It is the anterior horns that conduct the nerve impulse from the brain to the peripheral nerves. Also in the spinal cord in its central part there are structures that directly connect nerve cells anterior and posterior horns of the spinal cord - thanks to this, it is possible to form the so-called "mild reflex arc", when some movements occur unconsciously - that is, without the participation of the brain. An example of the work of a short reflex arc is pulling the hand away from a hot object.
Since the spinal cord has a segmental structure, therefore, each segment of the spinal cord includes nerve conductors from its area of responsibility. In the presence of an acute stimulus from the cells of the posterior horns of the spinal cord, excitation can abruptly switch to the cells of the anterior horns of the spinal segment, which causes a lightning-fast motor reaction. They touched a hot object with their hand - they immediately pulled their hand back. At the same time, pain impulses still reach the cerebral cortex, and we realize that we have touched a hot object, although the hand has already reflexively withdrawn. Similar neuroreflex arcs for individual segments of the spinal cord and sensitive peripheral areas may differ in the construction of the levels of participation of the central nervous system.
How does a nerve impulse reach the brain?
Further from the dorsal horns of the spinal cord pain sensitivity is sent to the overlying sections of the central nervous system along two paths - along the so-called "old" and "new" spinothalamic (path of the nerve impulse: spinal cord - thalamus) paths. The names "old" and "new" are conditional and speak only about the time of the appearance of these pathways in the historical period of the evolution of the nervous system. We will not, however, go into the intermediate stages of a rather complex neural pathway, we confine ourselves to stating the fact that both of these paths of pain sensitivity end in areas of the sensitive cerebral cortex. Both the “old” and “new” spinothalamic pathways pass through the thalamus (a special part of the brain), and the “old” spinothalamic pathway also passes through a complex of structures of the limbic system of the brain. The structures of the limbic system of the brain are largely involved in the formation of emotions and the formation of behavioral responses. It is assumed that the first, more evolutionarily young system (the “new” spinothalamic pathway) of pain sensitivity conduction draws a more defined and localized pain, while the second, evolutionarily older (“old” spinothalamic pathway) serves to conduct impulses that give a feeling of viscous, poorly localized pain. pain. In addition to this, the specified "old" spinothalamic system provides emotional coloring of pain sensation, and also participates in the formation of behavioral and motivational components of emotional experiences associated with pain.
Before reaching the sensitive areas of the cerebral cortex, pain impulses undergo a so-called preliminary processing in certain parts of the central nervous system. This is the already mentioned thalamus (optic tubercle), hypothalamus, reticular (reticular) formation, sections of the middle and medulla oblongata. The first, and perhaps one of the most important filters on the path of pain sensitivity is the thalamus. All sensations from external environment, from the receptors of the internal organs - everything passes through the thalamus. An unimaginable amount of sensitive and painful impulses passes every second, day and night, through this part of the brain. We do not feel the friction of the heart valves, the movement of the abdominal organs, various articular surfaces against each other - and all this is due to the thalamus.
In the event of a malfunction of the so-called anti-pain system (for example, in the absence of the production of internal, own morphine-like substances that arose due to the use of narcotic drugs), the aforementioned flurry of all kinds of pain and other sensitivity simply overwhelms the brain, leading to terrifying in duration, strength and severity emotional pain. This is the reason, in a somewhat simplified form, of the so-called “withdrawal” with a deficit in the intake of morphine-like substances from outside against the background of long-term use drugs.
How is the pain impulse processed in the brain?
The posterior nuclei of the thalamus provide information about the localization of the source of pain, and its median nuclei - about the duration of exposure to the irritating agent. The hypothalamus, as the most important regulatory center of the autonomic nervous system, is involved in the formation of the autonomic component of the pain reaction indirectly, through the involvement of centers that regulate metabolism, the work of the respiratory, cardiovascular and other body systems. The reticular formation coordinates already partially processed information. The role of the reticular formation in the formation of the sensation of pain as a kind of special integrated state of the body, with the inclusion of various biochemical, vegetative, somatic components, is especially emphasized. The limbic system of the brain provides a negative emotional coloring. The very process of understanding pain as such, determining the localization of the pain source (meaning a specific area own body) in conjunction with the most complex and diverse reactions to pain impulses occurs without fail with the participation of the cerebral cortex. Sensory areas of the cerebral cortex are the highest modulators of pain sensitivity and play the role of the so-called cortical analyzer of information about the fact, duration and localization of the pain impulse. It is at the level of the cortex that the integration of information from various kinds conductors of pain sensitivity, which means the full-fledged design of pain as a multifaceted and diverse sensation. At the end of the last century, it was revealed that each level of the pain system, from the receptor apparatus to the central analyzing systems of the brain, can have the property of enhancing pain impulses. Like a kind of transformer substation on power lines.
We even have to talk about the so-called generators of pathologically enhanced excitation. So, from the modern point of view, these generators are considered as the pathophysiological basis of pain syndromes. The mentioned theory of systemic generator mechanisms makes it possible to explain why, with a slight irritation, the pain response is quite significant in terms of sensations, why after the stimulus ceases, the sensation of pain continues to persist, and also helps to explain the appearance of pain in response to stimulation of skin projection zones ( reflex zones) in the pathology of various internal organs.
Chronic pain of any origin leads to increased irritability, reduced efficiency, loss of interest in life, sleep disturbance, changes in the emotional-volitional sphere, often leading to the development of hypochondria and depression. All these consequences in themselves increase the pathological pain reaction. The emergence of such a situation is interpreted as the formation of vicious circles: pain stimulus - psycho-emotional disorders - behavioral and motivational disorders, manifested in the form of social, family and personal maladjustment - pain.
Anti-pain system (antinociceptive) - role in the human body. Threshold of pain sensitivity
Along with the existence of a pain system in the human body ( nociceptive), there is also an anti-pain system ( antinociceptive). What does the anti-pain system do? First of all, each organism has its own genetically programmed threshold for the perception of pain sensitivity. This threshold allows us to explain why different people react differently to stimuli of the same strength, duration and nature. The concept of sensitivity threshold is a universal property of all receptor systems of the body, including pain. Just like the pain sensitivity system, the anti-pain system has a complex multilevel structure, starting from the level of the spinal cord and ending with the cerebral cortex. How is the activity of the anti-pain system regulated?
The complex activity of the anti-pain system is provided by a chain of complex neurochemical and neurophysiological mechanisms. The main role in this system belongs to several classes of chemicals - brain neuropeptides. They also include morphine-like compounds - endogenous opiates(beta-endorphin, dynorphin, various enkephalins). These substances can be considered so-called endogenous analgesics. These chemicals have a depressing effect on neurons of the pain system, activate anti-pain neurons, modulate the activity of higher nerve centers pain sensitivity. The content of these anti-pain substances in the central nervous system decreases with the development of pain syndromes. Apparently, this explains the decrease in the threshold of pain sensitivity up to the appearance of independent pain sensations against the background of the absence of a painful stimulus.It should also be noted that in the anti-pain system, along with morphine-like opiate endogenous analgesics, widely known brain mediators, such as: serotonin, norepinephrine, dopamine, play an important role. gamma-aminobutyric acid(GABA), as well as hormones and hormone-like substances - vasopressin (antidiuretic hormone), neurotensin. Interestingly, the action of brain mediators is possible both at the level of the spinal cord and the brain. Summarizing the above, we can conclude that the inclusion of the anti-pain system makes it possible to weaken the flow of pain impulses and reduce pain sensations. If there are any inaccuracies in the operation of this system, any pain can be perceived as intense.
Thus, all pain sensations are regulated by the joint interaction of the nociceptive and antinociceptive systems. Only their coordinated work and subtle interaction allows you to adequately perceive pain and its intensity, depending on the strength and duration of exposure to the irritating factor.
Every person, from the very early age, from time to time experiences pain in one or another point of his body. We experience a variety of pain sensations throughout our lives. And sometimes we don’t even think about what it is - pain, why does it arise and what does it signal?
What is pain
Various medical encyclopedias give approximately the following (or very similar) definition of pain: "an unpleasant sensation or suffering caused by irritation of specific nerve endings in damaged or already damaged tissues of the body." The mechanisms of the occurrence of pain at the moment are not yet fully understood, but one thing is obvious to physicians: pain is a signal that our body gives in case of certain disorders, pathologies, or the threat of their occurrence.
Types and causes of pain
Pain can be very different. And in medical literature, and in everyday conversations you can meet many various definitions the nature of the pain: "cutting", "stabbing", "piercing", "aching", "pressing", "dull", "throbbing" ... And this is not a complete list. But these are rather subjective characteristics of pain.
A scientific classification divides pain primarily into two large groups: acute and chronic. Or, as they are sometimes called, physiological and pathological.
Acute or physiological pain is of short duration and its cause is usually easily identified. Acute pain is usually clearly localized in a specific place in the body, and disappears almost immediately after the elimination of the cause that caused it. For example, acute pain occurs with injuries or with various acute diseases.
Chronic or pathological pain bothers a person for a long time, and its causes are far from always obvious. Almost always, chronic pain is caused by some long-term pathological processes. But it is sometimes very difficult to determine which ones exactly.
It should be noted that in some cases a person feels pain not at all in the place that is affected. In this case, they talk about reflected or radiating pain. The so-called phantom pain deserves special mention, when a person feels it in an absent (amputated) or paralyzed limb.
Psychogenic pain is also distinguished, the cause of which is not organic lesions, a mental disorders, strong emotional experiences, serious psychological problems: depression, hypochondria, anxiety, stress and others. Often they arise as a result of suggestion or self-hypnosis (often involuntary). Psychogenic pain is always chronic.
But, whatever the nature of the pain, it is always (with the exception, perhaps, of some phantom cases) a signal of some kind of trouble in the body. And therefore, in no case should you ignore even the weakest pain sensations. Pain is one of the main components of our defense system. With its help, the body tells us: “something is wrong in me, urgently take action!” This also applies to psychogenic pain, only in this case the pathology should be sought not in the anatomical or physiological, but in the mental sphere.
Pain as a symptom of various diseases
So, pain signals some kind of disturbance in the body. In other words, it is a symptom of certain diseases, pathological conditions. Let's find out in more detail what the pains in various points of our body say, in what diseases they occur.
Of all the sensory processes, the sensation of pain brings the greatest suffering.
Pain - mental condition arising as a result of super-strong or destructive effects on the body with a threat to its existence or integrity.
The clinical significance of pain as a symptom of a violation of the normal course physiological processes important, since a number of pathological processes of the human body makes itself felt in pain even before the appearance external symptoms diseases. It should be noted that adaptation to pain practically does not occur.
From the point of view of emotional experience, the sensation of pain has a depressing and painful character, sometimes the character of suffering, serves as a stimulus for various defensive reactions aimed at eliminating external or internal stimuli that caused the occurrence of this sensation.
Pain sensations are formed in the central nervous system as a result of combining processes that begin in receptor formations embedded in the skin or internal organs, impulses from which, through special pathways, enter the subcortical systems of the brain, which enter into dynamic interaction with the processes of the cortex of its cerebral hemispheres.
Cortical as well as subcortical formations are involved in the formation of pain. Pain occurs as a direct effect on the body external stimuli, and with changes in the body itself, caused by various pathological processes. Pain may arise or intensify according to a conditioned reflex mechanism and be psychogenic conditioned.
The pain reaction is the most inert and strong unconditioned reaction. The pain sensation is to a certain extent influenced by higher mental processes associated with the activity of the cortex and dependent on such personality traits as orientation, persuasion, value orientations, etc. Numerous examples testify both to courage, to the ability, when experiencing pain, not to succumb to it, but to act, obeying highly moral motives, and to cowardice, focusing on one's pain sensations.
The sensation of pain usually appears with the onset of the disease, the activation or promotion of the pathological process. The attitude of the patient is different to acute and chronic pain.
For example. With acute toothache, all the attention of a person is focused on the object of pain, he is looking for ways to get rid of pain by any means (taking various drugs, surgery, any procedures, just to relieve pain). Particularly hard to bear paroxysmal pain at chronic diseases, often the reaction to them intensifies over time. Patients expect them with fear, there is a feeling of hopelessness, hopelessness, despair. The pain in such cases can be so excruciating that a person waits for death as a release from torment.
In chronic pain, there may also be some adaptation to the sensations of pain and to the experiences associated with it.
Some doctors distinguish the so-called organic and psychogenic pain. The opposition of pain is not sufficiently substantiated, since all doctors are well aware that in a psychogenic situation, as a rule, there is an increase in pain that is of an organic nature.
The signal value of pain is a warning of imminent danger.
Severe pain is capable of completely capturing the thoughts and feelings of a person, focusing all his attention on himself. It can lead to sleep disturbances, various neurotic reactions.
Patients suffering from severe pain need an attentive and caring attitude to their complaints and requests. Pain is more debilitating to the patient than any other disorder.
Pain is an opportunity for the body to tell the subject that something bad has happened. Pain draws our attention to burns, fractures, sprains and advises us to be careful. There are a small number of people who are born without the ability to feel pain, they can endure the most severe injuries. As a rule, they die in the early period of maturity. Their joints wear out from excessive load, since, without feeling discomfort from a long stay in the same position; they do not change the position of the body for a long time. Without pain symptoms, infectious diseases, unnoticed in time, and various injuries to parts of the body proceed in a more acute form. But significantly more people who feel chronic pain(persistent or recurrent pain in the back, head, arthritis, cancer).
Nociceptive sensitivity(from lat. notion - I cut, I damage) - a form of sensitivity that allows the body to recognize harmful effects for it. Nociceptive sensitivity can be subjectively presented in the form of pain, as well as various interoreceptive sensations, such as heartburn, nausea, dizziness, itching, and numbness.
Pain arise as a response of the body to such influences that can lead to a violation of its integrity. characterized by a pronounced negative emotional coloring and vegetative shifts (increased heart rate, dilated pupils). In relation to pain sensitivity sensory adaptation practically absent.
Pain sensitivity determined by pain thresholds, among which are:
The lower one, which is represented by the amount of irritation at the first appearance of a sensation of pain,
The upper one, which is represented by the amount of irritation at which the pain becomes unbearable.
Thresholds of pain sensitivity vary depending on the general condition of the body and on cultural stereotypes. So, women are more sensitive to pain during periods during ovulation. In addition, they are more sensitive to electrical stimulation than males, but have the same sensitivity to extreme thermal stimulation. Representatives of traditional peoples are more resistant to pain.
Unlike, for example, vision, pain is not localized in any particular nerve fiber that connects the receptor to the corresponding area of the cerebral cortex. There is also no single type of stimulus that causes pain (as, say, light irritates vision), and there are no specific pain receptors (like the rods and cones of the retina). Irritants that cause pain, in small doses, can also cause other sensations, such as a feeling of heat, cold, smoothness or roughness.
Theories of pain. There were two alternative positions in the interpretation of the specificity of pain reception. One position was formed by R. Descartes, who believed that there are specific pathways coming from specific pain receptors. The more intense the flow of impulses, the stronger pain. Another position was presented, for example, by Goldscheider (1894), who denied the existence of both specific pain receptors and specific ways pain conduction. Pain occurs whenever too much flow of stimuli associated with other modalities (skin, auditory, etc.) enters the brain. Currently, it is believed that there are still specific pain receptors. So, in Frey's experiments, it was proved that there are special pain points on the surface of the skin, the stimulation of which does not cause any other sensations than pain. These pain points are more numerous than pressure or temperature sensitive points. It is also possible to make the skin insensitive to pain with morphine, but other types of skin sensitivity are not changed. Free nerve endings, also located in the internal organs, act as nocireceptors.
Pain signals are transmitted through the spinal cord to the nuclei of the thalamus and then to the neocortex and limbic system. Along with non-specific mechanisms of pain sensations, which are activated when any afferent nerve conductors are damaged, there is a special nervous apparatus of pain sensitivity with special chemoreceptors that are irritated by kinins formed when blood proteins interact with damaged tissues. Kinins can be blocked by painkillers (aspirin, pyryramidone).
It's interesting how pain is remembered. Experiments show that after medical procedures people forget about the duration of pain. Instead, the moments of the strongest and final pain sensations are recorded in memory. D. Kahneman and his colleagues established this when they asked the participants of the experiment to dip one hand into the icy water that causes pain and hold it in it for 60 seconds, and then the other hand in the same water for 60 seconds, plus another 30 seconds, but water for these 30 seconds no longer caused such strong pain. And when the participants in the experiment were asked which procedure they would like to repeat, the majority wished to repeat a longer procedure, when the pain, although it lasted longer, weakened at the end of the procedure. When patients recalled pain experienced during a rectal examination a month later, they also remembered better the last (and also the most painful) moments, rather than the total duration of the pain. This leads to the conclusion that it is better to slowly relieve pain during a painful procedure than to abruptly end the procedure at the most painful moment. In one experiment, a doctor did this during a rectal examination procedure - he extended the procedure by one minute and made it so that during this time the pain of the patient decreased. And although an additional minute of discomfort did not reduce the overall duration of pain during the procedure, patients still later recalled this procedure as less painful than one that lasted less in time, but ended at the most painful moment.
Types of pain. It has long been noted that the conscious infliction of additional pain on oneself contributes to a decrease in the subjective strength of pain. So, for example, Napoleon, who suffered from kidney stones, interrupted this pain by burning his hand in the flame of a candle. This raises the question of what should probably be said about different types pain.
It has been found that there are two types of pain:
Pain, transmitted by large, fast-conducting nerve fibers (L-fibers), is sharp, distinct, fast-acting, and appears to originate in specific areas of the body. it warning system body, indicating that it is urgent to remove the source of pain. This type of pain can be felt when pricked with a needle. The warning pain disappears quickly.
The second type of pain is also transmitted by slowly conducting nerve fibers (S-fibers) of small diameter. This is slow, aching, Blunt pain, which differs widespread and very unpleasant. Such pain intensifies if irritation is repeated. It is a pain reminder system, it signals to the brain that the body has been damaged and movement needs to be restricted.
Although there is no generally accepted theory of pain control gate theory (or sensory locking), created by psychologist R. Melzak and biologist P. Wall (1965, 1983), is considered as the most reasonable. In accordance with it, it is believed that there is a kind of nerve "gate" in the spinal cord, which either blocks pain signals or allows them (relief) to go to the brain. They noticed that one kind of pain sometimes overwhelms another. Hence the hypothesis was born that pain signals from various nerve fibers the same nerve "gates" in the spinal cord pass through. If the gate is "closed" by one pain signal, other signals cannot pass through it. But how do the gates close? The signals transmitted by the large, fast-acting nerve fibers of the warning system seem to close the spinal pain gate directly. This prevents the slow pain of the "reminding system" from reaching the brain.
Thus, if the tissue is damaged, the small fibers become activated, opening the neural gates, and the sensation of pain occurs. Activation of large fibers leads to the closure of the gate for pain, as a result of which it subsides.
R. Melzak and P. Wall believe that the gate control theory explains the analgesic effects of acupuncture. Clinics use this effect by applying a small electric current to the skin: this stimulation, felt only as a slight tingle, can greatly relieve more excruciating pain.
In addition, pain can be blocked at the level of the spinal gate by increasing general arousal, the appearance of emotions, including during stress. These cortical processes activate fast L-fibers and thereby block access to information transfer from S-fibers.
Also, the gate before pain can be closed with the help of information that comes from the brain. Signals that travel from the brain to spinal cord, help to explain examples psychological impact for pain. If a different ways divert attention from pain signals, the sensation of pain will be much less. Injuries received in sports games, may not be noticed until taking a shower after the game. While playing basketball in 1989, Ohio State University player J.Berson broke his neck, but continued to play.
This theory also explains the occurrence of phantom pain. Just as we see a dream with our eyes closed or hear a ringing in complete silence, so 7 out of 10 cripples have amputated limbs that hurt (in addition, they may seem to be moving). This phantom limb sensation suggests that (as in the examples of vision and hearing) the brain may misunderstand the spontaneous activity of the central nervous system that occurs in the absence of normal sensory stimulation. This is explained by the fact that after amputation there is a partial regeneration of nerve fibers, but primarily of the S-fiber type, but not of the L-fiber type. Because of this, the spinal gate always remains open, which leads to phantom pain.
Pain control. One way to relieve chronic pain is to stimulate (massage, electro-massage, or even acupuncture) large nerve fibers to block the path for pain signals. If you rub the skin around the bruise, then additional irritation is created, which will block some of the pain signals. Ice on the bruised area not only reduces swelling, but also sends cold signals to the brain that close the gate to pain. Some people with arthritis may carry a small, portable electrical stimulator near the affected area. When it irritates the nerves in a sore spot, the patient feels a vibration rather than pain.
Depending on the symptoms in clinical setting choose one or more ways to relieve pain: medicines, surgical intervention, acupuncture, electrical stimulation, massage, gymnastics, hypnosis, auto-training. So, the well-known preparation according to the Lamaze method (preparation for childbirth) just includes several of the above methods. Among them are relaxation (deep breathing and muscle relaxation), counterstimulation ( light massage), distraction (concentration of attention on some pleasant subject). After E. Worthington (1983) and colleagues conducted several such sessions with women, the latter were easier to endure. discomfort associated with holding hands in ice water. The nurse may distract the attention of patients who are afraid of injections, affectionate words and asking to look somewhere as he inserts the needle into the body. Beautiful view to a park or garden from the window of a hospital room also has a positive effect on patients, helps them to forget unpleasant feelings. When R. Ulrich (1984) got acquainted with medical records patients at the Pennsylvania Hospital, he concluded that patients who were treated in wards overlooking the park needed less medication, they left the hospital faster than those who lived in cramped wards, the windows of which overlooked a blank brick wall.
