Every person, from a very early age, from time to time experiences pain in one or another point of his body. With a variety of pain we face throughout life. And sometimes we do not even think about what it is - pain, why does it arise and what does it signal?

What is pain

Various medical encyclopedias give about this (or very similar) definition of pain: “an unpleasant sensation or suffering caused by irritation of particular nerve endings in damaged or already damaged tissues of the body”. The mechanisms of pain at the moment are not fully understood, but one thing is clear to the doctors: pain is a signal that our body gives for certain violations, pathologies, or the threat of their occurrence.

Types and causes of pain

The pain can be very different. Both in the medical literature and in everyday conversations one can come across many different definitions of the nature of pain: “cutting”, “piercing”, “piercing”, “aching”, “pressing”, “dull”, “pulsing” ... And this far from complete list. But these are quite subjective characteristics of pain.

A scientific classification divides the pain in the first place into two large groups: acute and chronic. Or, as they are sometimes called, physiological and pathological.

Acute, or physiological pain - short-term, and its cause, as a rule, is easily identified. Acute pain is usually clearly localized in a particular place in the body, and passes almost immediately after the cause has been eliminated. For example, acute pain occurs in injuries or in various acute diseases.

Chronic or pathological pain has been bothering a person for a long time, and its causes are not always obvious. Almost always chronic pain is caused by some kind of long-term pathological processes. But it is sometimes very difficult to determine exactly which ones.

It should be noted that in some cases, the person feels the pain is not at all in the place that is affected. In this case, they say about the reflected or radiating pain. Special mention deserves the so-called phantom pain, when a person feels it in the missing (amputated) or paralyzed limb.

Psychogenic pain is also distinguished, the cause of which is not organic lesions, but mental disorders, strong emotional distress, serious psychological problems: depression, hypochondria, anxiety, stress, and others. Often they arise as a result of suggestion or auto-suggestion (often involuntary). Psychogenic pain is always chronic.

But, whatever the nature of the pain, it is always (with the exception of, perhaps, some cases of phantom) is a signal of some kind of trouble in the body. And therefore, in no case should we ignore even the weakest pain. Pain is one of the main components of our defense system. With its help, the body tells us: “something is amiss in me, take urgent measures!” 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, the pain signals some disturbances 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 certain points of our body are talking about, in which diseases they arise.

Pain is an important adaptive response of the body, having the meaning of an alarm.

However, when 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 effects of a damaging factor. It is manifested by vegetosomatic reactions and is characterized by certain psycho-emotional changes.

The term "pain" has several definitions:

- it is a kind of psycho-physiological condition resulting from exposure to superstrong or destructive stimuli that cause organic or functional disorders in the body;
   - In a narrower sense, pain (dolor) is a subjective sensation that arises as a result of exposure to these super-strong stimuli;
   - pain is a physiological phenomenon informing us about the harmful effects damaging or representing a potential danger to the body.
   Thus, pain is both a preventive and a defensive reaction.

   The International Association for the Study of Pain provides the following definition of pain (Merskey, Bogduk, 1994):

Pain is an unpleasant sensation and emotional experience associated with actual and potential tissue damage or a condition described by the words of such a lesion.

The phenomenon of pain is not limited solely to organic or functional impairments at its location, pain also affects the activity of the organism as an individual. For many years, researchers have described the incalculable number of adverse physiological and psychological consequences of unrelieved pain.

The physiological consequences of unresolved pain of any location can include everything from deterioration of the gastrointestinal tract and respiratory system and to increased metabolic processes, increased growth of tumors and metastases, decreased immunity and lengthening the healing time, insomnia, increased blood clotting, loss of appetite and decrease in working capacity.

The psychological effects 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, reduced sexual activity, which leads to family conflicts and even to a request for euthanasia.

Psychological and emotional effects often influence a patient’s subjective response, exaggerating or minimizing the significance of pain.

In addition, the degree of self-control of pain and illness of 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 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 painful behavior. This means that the effectiveness of diagnosis and treatment is determined not only by the ability to identify the etiopathogenetic mechanisms of the physical condition, manifested or accompanied by pain, but also the ability to see behind these manifestations the problems of limiting the patient’s usual life.

A considerable amount of work, including monographs, is devoted to the study of the causes of the onset and pathogenesis of pain and pain syndromes.

As a scientific phenomenon, pain has been studied for over a hundred years.

There are physiological and pathological pain.

Physiological pain occurs at the time 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. The behavioral response interrupts communication with the source of the damage.

Pathological pain can occur both in receptors and in nerve fibers; it is associated with long-term healing and is more destructive due to the potential threat of disrupting the normal psychological and social existence of the individual; the behavioral reaction in this case is 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 that allow it to recognize its causes, mechanisms and localization.

Types of pain

First type  - acute pain caused by damage to the tissue, which decreases as it heals. Acute pain has a sudden onset, short duration, clear localization, appears when exposed to intense mechanical, thermal or chemical factors. It can be caused by an infection, injury, or surgery, lasting for several hours or days, and is often accompanied by signs such as rapid heartbeat, sweating, pallor, and insomnia.

Acute pain (or nociceptive) refers to pain that is associated with the activation of nociceptors after tissue damage, corresponds to the degree of tissue damage and the duration of action of damaging factors, and then fully 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 bear a protective function and causes the patient to suffer, it is not accompanied by signs characteristic of acute pain.

Intolerable chronic pain has a negative effect on a person’s psychological, social and spiritual life.

With continuous stimulation of pain receptors, the threshold of their sensitivity decreases with time, and non-pain impulses also begin to cause pain. Development chronic pain  Researchers associate with unhealed acute pain, emphasizing the need for adequate treatment.

Untreated pain later leads not only to the material burden on the patient and his family, but also entails enormous costs for society and the health care system, including longer hospitalization periods, disability, repeated visits to outpatient clinics (emergency centers). Chronic pain is the most common cause of long-term partial or complete disability.

There are several classifications of pain, one of them, see table. one.

Table 1. Pathophysiological classification of chronic pain

Pain classification

Somatic pain occurs when damage or stimulation of the skin of the body, as well as damage to deeper structures - muscles, joints and bones. Bone metastases and surgery are common causes of somatic pain in patients with tumors. Somatic pain, as a rule, is constant and quite clearly limited; it is described as throbbing pain, gnawing pain, etc.

Visceral pain

It is described as deep, constricting, generalized, and may radiate to the skin. Visceral pain, as a rule, is constant, it is difficult for the patient to establish its localization. Neuropathic (or deafferentational) pain occurs when nerve damage or irritation.

It may be permanent or unstable, sometimes firing, and is usually described as sharp, stabbing, cutting, burning, or as an unpleasant sensation. In general, neuropathic pain is the most serious in comparison with other types of pain, it is more difficult to treat.

Clinically pain

This classification may be useful for initial therapy, however, such a division is impossible in the future because of the close combination of these pains.

Nocigenic pain

Pain in case of damage to internal organs is a result of rapid contraction, spasm, or stretching of smooth muscles, because the smooth muscles themselves are not sensitive to heat, cold, or dissection.

The pain from internal organs that have sympathetic innervation can be felt in certain areas on the surface of the body (Zakharyin-Ged zone) - this is reflected pain. The most famous examples of such pain are pain in the right shoulder and right side of the neck with gall bladder damage, pain in the lower back with disease. bladder  and finally the pain in the left hand and the left half chest  with 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 remote areas of the body surface, but this does not explain the reason for the reflection of pain from the organ to the surface of the body.

Nocigenic type of pain is therapeutically sensitive to morphine and other narcotic analgesics.

Neurogenic pain

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 central nervous system damage is usually caused by cerebrovascular catastrophe — this is known under the classic name of “talamic syndrome”, although studies (Bowsher et al., 1984) show that in most cases the lesions are located in areas other than the thalamus.

Many pains are mixed and clinically manifest by nocigenic and neurogenic elements. For example, tumors cause tissue damage and nerve compression; in diabetes, nocigenic pain arises from peripheral vascular lesions, and neurogenic pain due to neuropathy; with herniated discs that compress the nerve root, the pain syndrome includes a burning and shooting neurogenic element.

Psychogenic pain

It is reinforced in hysterical personalities, and more accurately reflects the reality in non-steroid-type patients. It is known that people of different ethnic groups differ in the perception of postoperative pain.

Patients of European descent have less intense pain than American negros or Hispanics. They also have low pain intensity compared with Asians, although these differences are not very significant (Faucett et al., 1994). Some people are more resistant to the development of neurogenic pain. Since this trend has the aforementioned ethnic and cultural characteristics, it seems inherent. Therefore, the prospects for research aimed at locating and isolating the "pain gene" are so attractive (Rappaport, 1996).

Any chronic illness or illness that is accompanied by pain affects the personality's emotions and behavior.

Pain often leads to anxiety and tension, which themselves increase the perception of pain. This explains the importance of psychotherapy in controlling pain. Biofeedback, relaxation training, behavioral therapy and hypnosis, used as psychological interventions, are useful in some persistent, refractory to treatment cases (Bonica, 1990, Wall, Melzack, 1994, Hart, 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

Pain I

In the description of patients, the pain in their nature can be acute, dull, cutting, stabbing, burning, oppressive (compressive), aching, pulsating, According to the duration and frequency they can be constant, paroxysmal, associated with the time of day, seasons of the year, exercise , body posture, with certain movements (for example, breathing, walking), eating, acts of defecation or urination, etc., which makes it possible to suspect localization and pathology causing pain. Features of the accompanying pain of emotional reactions, such as the feeling of fear of death, accompanying chest B. with angina, myocardial infarction, pulmonary thromboembolism, have diagnostic value.

A definite diagnostic orientation is given by the distinction between somatoglia, pains caused by irritation of the somatic nerve fibers, and vegetalgy (sympatalgia), arising from the involvement in the sensitive fibers of the vegetative innervation. Somatalgia (permanent or paroxysmal) are located in the innervation zone of the peripheral nerves or roots and are usually not accompanied by vegetative disturbances or the latter (with very intense pain) have a character (general, increased blood pressure, increased heart rate, etc.).

In vegetalgia, disorders of the vegetative functions are observed as a rule and often have a local character, as expressed by local spasms of peripheral vessels, changes in skin temperature, "goose" skin, impaired sweating, trophic disorders, etc. Sometimes vegetalgia reaches causalgia (causalgia) ,   Often with reflected pains of the type of repercussion (Repercussion) with the appearance of pain in the Zakharyin-Ged zones. Perhaps the appearance of pain in one half of the body (), which is observed, in particular, with the defeat of the thalamus. The high frequency of repercussion with the appearance of pain in areas remote from the affected organ should be borne in mind in the differential diagnosis of diseases of internal organs, blood vessels, bones and joints. for example, in myocardial infarction (myocardial infarction) B. is possible not only in the region of the sternum with irradiation in left hand, but also B. in the thoracic spine, B. in the lower, in the forehead, in right hand, in the abdomen (abdominal form), etc. With all the variety of manifestations of painful repercussion, the total B. characteristic helps to identify features that are typical or atypical for any process in the area of ​​internal organs. for example, dissecting aortic aneurysm in many of B.'s characteristics is similar to myocardial infarction, but B.'s spread along the spine with irradiation to the legs, which is characteristic of dissecting aneurysm, is not typical of myocardial infarction.

The behavior of the patient during painful paroxysms also has diagnostic value. for example, in myocardial infarction, the patient tries to lie still, the patient rushes about with a bout of renal colic, adopts various postures, which is not observed when B. is similarly localized in a patient with lumbar radiculitis.

In diseases of the internal organs of a bladder, it occurs as a result of blood flow disorders (, thrombosis of the mesenteric or renal arteries, atherosclerotic stenosis of the abdominal aorta, etc.); spasm of smooth muscles of internal organs (stomach,); stretching the walls of hollow organs (gallbladder, renal pelvis, ureter); the spread of the inflammatory process in areas supplied with sensitive innervation (to the parietal pleura, peritoneum, etc.). brain substance is not accompanied by B., it occurs when the irritation of the membranes, venous sinuses, intracranial vessels. Pathological processes in a lung are followed by B. only at their distribution on a parietal pleura. Strong B. occur when a spasm of heart vessels. B. in the esophagus, stomach and intestines often occurs when their spastic condition or stretching. Pathological processes in the parenchyma of the liver, spleen, kidneys do not cause pain, unless they are accompanied by acute stretching of the capsule of these organs. Muscle pain occurs with bruises, myositis, convulsions, disorders of the arterial circulation (in the latter cases, B. proceeds as sympathalgia). With the defeat of the periosteum and bone processes B. are extremely painful in nature.

It must be borne in mind that pain in cases of diseases of internal organs may not persist for a long time and will only grow in an avalanche-like manner during the incurable stage of the process (for example, malignant neoplasms). After the cure of a somatic disease, persistent pain is possible due to the consequences of damage to the nerve trunks, their ischemic changes, adhesive process, changes in the functional state of the preganglionic vegetative innervation nodes, as well as psychogenic pain fixation.

The elimination of pain as one of the most painful for the patient manifestations of the disease refers to the priorities that are solved by the doctor in the process of determining therapeutic tactics. The best option is to eliminate the cause of the pain, such as removing a foreign body or squeezing, repressing dislocation, etc. If this is not possible, preference is given to influences on those pathogenesis links with which pain is associated, for example, alkali intake to relieve pain during ulcer duodenal ulcer, nitroglycerin - with angina pectoris, antispasmodics (see. Antispasmodics) and anticholinergics (see Holoblokiruyuschie means) - with hepatic and renal colic, etc. With the ineffectiveness or impossibility of causal and pathogenetic therapy, they resort to symptomatic treatment of pain with the help of analgesics (Analgesics) ,   the effect of which can be enhanced by the simultaneous use of neuroleptic agents (Neuroleptic agents) or tranquilizers (tranquilizers) .   However, with the unspecified nature of the somatic disease, especially with unclear abdominal pains, the use of analgesics is contraindicated due to the possible modification of the clinical picture that makes it difficult to diagnose the disease, in which urgent surgical intervention may be indicated (see Acute abdomen) . With local pains, incl. with some neuralgia, local anesthesia is sometimes advisable. .   For persistent debilitating pains in patients with chronic diseases and low effectiveness of analgesics, symptomatic surgical B. is used - radicotomy, chordotomy, tractotomy and other methods.

  Bibliography:  Waldman A.V. and Ignatov Yu.D. The central mechanisms of pain, L., 1976, bibliogr .; Grinshtein A.M. and Popova N.A. Vegetative syndromes, M., 1971; Erokhina L.G. Facial pain, M., 1973; Kalyuzhny L.V. Physiological mechanisms of regulation of pain sensitivity, M., 1984, bibliogr .; Karpov V.D. nervous diseases, M., 1987; Kassil G.N. The science of pain, M., 1975; Kryzhanovsky G.N. Determinant structures in the pathology of the nervous system, M., 1980; Nordemar R. Back pain,. With Swedish., M., 1988; Shtok V.N. , M., 1987, bibliogr.

Fig. 1. Scheme of occurrence of projected pain. Nerve impulses caused by direct stimulation (indicated by an arrow) reach the corresponding zone of the cerebral cortex along the afferent fibers in the spinotalamic tract, causing a sensation of pain in that part of the body (arm), which is usually caused by irritation of the nerve endings: 1 - a part of the body with pain receptors; 2 - the sensation of pain at the location of the respective receptors of pain; 3 - the brain; 4 - lateral spinothalamic tract; five - spinal cord; 6 - afferent nerve fiber.

Fig. 2. Diagram of the occurrence of reflected pain. Pain from the internal come to the spinal cord, the individual structures of which are synaptically in contact with the nerve cells of the spinothalamic tract, on which the nerve fibers innervating a certain segment of the skin end: 1 - skin; 2 - the trunk of the sympathetic nervous system; 3 - rear spine; 4 - lateral spinothalamic tract; 5 - spinal cord; 6 - front spine; 7 - internal organ; 8 - the visceral nerve.