Depression is an ancient mechanism that allows multicellular organisms to recognize tissue damage and take measures to protect the body. Emotion plays a significant role in understanding pain. Even the intensity of the common physiological pain largely depends on the emotional perception of a person as someone hardly tolerates discomfort from small scratches, and someone can efficiently treat teeth without anesthesia. Thousands of studies have been devoted to this phenomenon, but there is still no complete understanding of such interconnections. Traditionally, the neurologists define pain threshold with the help of a needle, but this method does not give an objective picture.
Pain threshold and its “height” depends on several factors:
• the genetic factor — there are “hypersensitive” and “insensible” families;
• psychological status — the presence of anxiety, depression and other mental disorders;
• previous experience — if the patient has already experienced pain in a similar situation, then the next time he or she will perceive it more acutely;
• various diseases — if diabetes mellitus increases the pain threshold, some neurological disorders, on the contrary, reduce it.
One of the most important classifications of pain is by its type. Each of them has specific signs and characteristic of a particular group of pathological conditions. Having established the kind of pain, the doctor can reject some of the possible diagnoses and form a reasonable treatment plan. This classification divides pain into nociceptive, neuropathic and psychogenic.
Nociceptive pain is usually an acute physiological pain that signals about injury or illness. It has a warning function. As a rule, its source is clearly defined — pain in muscles and bones with a bruise, pain during suppuration (abscess) of the subcutaneous tissue. There is also a visceral variant of nociceptive pain, and its source is internal organs. Even though emotional distress is not so clearly localized, each organ has its own “pain profile.” Depending on the place and conditions of occurrence, the doctor determines the cause of the pain. Thus, heart pain can spread to half of the chest, to the arm, shoulder, and jaw. If there are similar symptoms, the doctor will first exclude heart disease.
Also, the conditions for the occurrence of pain are essential. If it occurs while walking and stops during stasis, it is a significant argument in favor of its cordial origin. If a similar pain occurs when a person is lying or sitting, the doctor will think about the esophagus and its inflammation. In any case, nociceptive pain is an important clue when searching for an organic disease (inflammation, tumor, ulcer).
Neuropathic pain is associated with damage to the nervous system itself, and with injury at any level — from peripheral nerves to the brain. Such depression is characterized by the absence of an apparent disease outside the nervous system and is usually described as “piercing,” “cutting,” or “burning.” Often, neuropathic pain is combined with sensory, motor, and autonomic disorders of the nervous system.
Depending on the damage to the nervous system, pain can manifest on the periphery in the form of a burning sensation and a feeling of coldness in the legs (with diabetes, an alcoholic illness) and at any level of the spinal column with spreading to the chest, front wall of the abdomen and limbs (with radiculitis). Also, pain can be a sign of a single nerve lesion (trigeminal neuralgia, postherpetic neuralgia) or create a sophisticated palette of neurological symptoms if the pathways in the spinal cord and brain are damaged.
Psychogenic pains occur in various mental disorders (for example, depression). It can mimic the disease of any organ, but unlike a real illness, complaints are characterized by extraordinary intensity and monotony. The pain can last continuously for many hours, days, months and years. The patient describes these conditions as "painful" and "exhausting." Sometimes painful sensations can reach such intensity that a person is hospitalized with suspected myocardial infarction or acute appendicitis. The exclusion of organic disease and the many-month / long-term history of pain is a sign of its psychogenic nature.
Initially, nociceptive receptors react to injury, but after a while, if their irritation does not repeat, the signal from them subsides. At the same time, an antinociceptive system that suppresses pain is activated — the brain reports that it has received enough information about the occurrence. In the acute phase of trauma, if the excitation of nociceptive receptors is excessive, opioid analgesics block pain the best.
A couple of days after the injury, the pain intensifies again, but this time due to swelling, inflammation and the production of inflammatory substances (prostaglandins). In this case, non-steroidal anti-inflammatory drugs are effective. As the wound heals, if a nerve is involved in the process, neuropathic pain may occur. Non-steroidal media and opioids poorly control neuropathic pain, so the optimal solution for it is anticonvulsants and some antidepressants.
Pain does not always indicate the presence of a disease. The discomfort in the muscles after training is a variation of physiological pain, which reflects the restructuring of myofibrils. Short, randomly directed myofibrils are destroyed, the tissue is remodeled under the newly assigned tasks — growing loads in a particular direction. However, acute and chronic pain almost always report about pathology or trauma. Chronic pain may be associated with persistent organic disease, for example, with a growing tumor, but most often the source is no longer present, and the pain sustains itself through the mechanism of the pathological reflex. An excellent model of self-sustaining chronic pain can be called myofascial pain syndrome when constant muscle spasm provokes anxiety, which, in turn, strengthens muscle spasm.
We often experience pain, and there is no need to consult a doctor every time, mainly if the pain is already known and we know its cause and can cope with it. In the case of new illness, when a person does not understand its nature, or pain, accompanied by alarming symptoms (nausea, diarrhea, constipation, shortness of breath, fluctuations in pressure and body temperature), you need to contact a specialist. Sometimes, to get rid of painful sensations, it is enough to choose a painkiller and teach a person to avoid the causes of pain, for example, to prevent physical inactivity with the myofascial syndrome.