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Why is the body temperature lower than 36, 35.5: which means what to do?

 
, medical expert
Last reviewed: 23.04.2024
 
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A person is homeothermic, that is, warm-blooded, and has a constant temperature, which during the day can range from + 36.5 ° C to + 37 ° C. But any temperature above or below this range is abnormal. And if the body temperature is below normal, then not all body systems function correctly.

Body temperature is an indicator of the amount of heat produced by the body in the process of basic metabolism. And the process of its regulation occurs at the reflex level - in the hypothalamus, which refers to the parts of the intermediate brain. The function of the hypothalamus also includes the control of the work of our entire endocrine and autonomic nervous system, and in it, in addition to the centers regulating body temperature, there are "levers of control" of hunger and thirst, a cycle of sleep and wakefulness, as well as many other important physiological and psychosomatic processes.

Lethally low body temperature

A potentially fatal condition in which the body temperature of a person falls below + 35 ° C, in medicine is defined as  hypothermia.

It can be moderate - with a body temperature of 32.2-35 ° C, and a heavy one - with 30.5-32.2 ° C. Deadly or critically low body temperature - less than 30 ° C, and this is a deep degree of hypothermia.

The effect of lowering the temperature on the body - when the body temperature is low, 35, 34.5, 34 ° C - is manifested by a violation of coordination of movements. Also, the first signs include pallor of the skin (with cyanosis of the lips, ears, fingers and toes) and a strong tremor that arises from the loss of heat: in order to replenish it, the brain triggers physiological reactions, and involuntary muscle contractions in the form of tremors, contribute to the production of heat by accelerating the metabolism.

If the cold stress is too high, at a mark between 32.2 and 30 ° C, the tremor stops, and then symptoms such as loss of orientation, decreased vision, incoherence of speech, stiffness of the muscles, stupor, decrease in pulse and respiration rate. However, a short-term acceleration of the heart rhythm (in the form of ventricular tachycardia) is possible, but when the deadly low body temperature is 28 ° C or lower, ventricular fibrillation begins. The body quickly dehydrates, the liver and kidneys cease to function, and clinical death occurs.

Statistics show that it is possible to survive hypothermia, but mortality from severe and profound hypothermia remains high and is estimated at 38-75%.

All this - the primary hypothermia, in which the mechanisms of body thermoregulation work normally (that is, the person is healthy), but the body undergoes severe hypothermia. And then we will talk about secondary hypothermia, when the body temperature is below 35-36 ° C. It is often called the  violation of thermoregulation, which has many causes.

Causes of low body temperature

Body temperature below + 36 ° C is possible in practically healthy people, for example, with chronic fatigue syndrome or lack of vitamins, primarily ascorbic acid.

If there is a low body temperature in the morning, then this is the result of its physiological decline - from two in the morning to six in the morning (to about 36.3 ° C). At high physical exertion and overwork during the day, there may be a low body temperature in the evening. From a medical point of view, the basal low body temperature at night - while the muscles are relaxed and the heat production is slowed down - is due to the lack of thermoregulatory reactions (in the interval between two and four hours).

Nevertheless, attention should be paid to possible metabolic problems: a decrease in nighttime temperature may be the result of an elevated blood glucose level in people with diabetes. At the same time, the absorption of glucose in the body is not enough to generate energy, which slows down the metabolic rate and disrupts the temperature homeostasis.

Low body temperature after the disease, especially infectious-inflammatory, is associated with a general weakening of the body. Also, the use of certain drugs may affect: antipyretics (antipyretic drugs); drugs that block alpha and beta-adrenergic receptors (used in cardiovascular pathologies); psychotropic, sedative, local anesthetics.

In surgery, low body temperature after surgery (within 24 hours after the onset of general anesthesia and the onset of surgery) is the result: suppression of hypothalamic function by drugs for inhalation or intravenous anesthesia; temporary disturbance of blood flow, as well as increase in heat loss, which during the operation simply can not be compensated by the patient's body.

In most cases, low body temperature during pregnancy can indicate anemia, which is a consequence of iron deficiency and a lack of red blood cells carrying oxygen. Pregnant women are at increased risk of developing anemia, which is accompanied by a feeling of fatigue, dizziness and headaches. Therefore, if the future mother has headaches and low body temperature, you should check the hemoglobin level in the blood.

Midwives claim that low body temperature in early pregnancy (during the first 6-8 weeks) lasts longer than 10-14 days, it is a risk factor for its spontaneous interruption (miscarriage).

In parturients, low body temperature after childbirth can be a manifestation of postpartum sepsis, especially when vomiting begins and it becomes difficult to breathe. In addition, low temperature parameters after childbirth with great blood loss are characteristic for  Shihan syndrome  (other names for this pathology: ischemic necrosis of the pituitary gland, diencephalic-pituitary cachexia, postpartum hypopituitarism, Simmonds disease).

As you know, the basal body temperature in women varies during the menstrual cycle, and low body temperature with menstruation is noted after their end - with the next decrease in the level of estradiol and estrogen (if pregnancy has not occurred).

In women during menopause, cardinal changes occur in the hormonal sphere, and low body temperature with menopause is due to a sharp reduction in the synthesis of estrogen. The thermoregulation system responds to this by a slight decrease in temperature and nighttime hyperhidrosis (increased sweat secretion).

By the way, low body temperature in men over 50 years is often associated with a decrease in testosterone levels, and in men of any age - with alcohol intoxication.

Parents should be aware that the child's low body temperature can also be a symptom of diabetes or anemia. But, perhaps, it is the reaction of the child's organism to the treatment of the common cold by instillation into the nose of Naphthyzin, Nazol or Otrivin (and other means narrowing the blood vessels).  

In the first two months after birth, low body temperature in the infant (especially premature) is the hypothermic reaction of the period during which the child's thermoregulatory system adapts. However, pediatricians remind us that a decrease in temperature can be caused by malnutrition, if the mother does not have enough breast milk. In addition, low body temperature and diarrhea in an infant is a consequence of congenital lactase deficiency (inability to absorb milk sugar).

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Low body temperature as a sign of disease

In medicine, the causes of low body temperature are associated with various diseases, as temperature indicators are on the list of their symptoms. And the first signs of a decrease in temperature are manifested by general malaise, weakness, chilliness and increased drowsiness.

The low body temperature for colds, which rhinoviruses most often cause, is a consequence of weakened immunity, insufficient production of endogenous interferon, and a decrease in total metabolism. Therefore, quite often the catarrhal conditions accompany chills at a low body temperature.

For the same reason, it is not unusual and low body temperature for bronchitis (chronic or obstructive), as well as low body temperature and cough with phlegm in pneumonia. And most patients with pneumonia do not know that low body temperature and weakness also relate to the symptoms of this disease. Also, it breaks the body, it makes vomiting, and there can be vomiting.

Low body temperature in tuberculosis is noted by phthisiatricians very rarely: with extrapulmonary localization of the disease accompanied by autonomic disorders.

Weakness, headache, dizziness and low body temperature, as well as nausea and excessive sweating are included in the list of symptoms of vegetative-vascular dystonia, which is characterized by instability of blood pressure.

Many patients with  Parkinson's disease  have basal low body temperature and low blood pressure (orthostatic hypotension); the pathogenesis of this disorder is associated with degenerative processes in the cells of the hypothalamus.

It is not uncommon for patients to have a constantly low body temperature. In this condition, first of all, there is a suspicion of a violation of the functions of the hypothalamus itself, which occurs due to genetic pathologies, brain or spinal cord injuries, stroke, inflammation and cerebral edema. It is necessary to take into account such risk factors for the development of the hypothalamic syndrome as ionizing radiation, tumors and brain operations, as well as general exhaustion of the body - cachexia (often caused by anorexia nervosa or "hungry" diets).

A pronounced hypothalamic syndrome is characterized by high blood pressure at low body temperature, increased heart rate, flushes of blood to the head, low body temperature and sweating.

In case of problems with the thyroid gland, in particular, its inflammation (thyroiditis), the patients are noted: low body temperature and weakness, fatigue and daytime drowsiness, headaches and low body temperature. In this case, the pathogenesis lies in the decrease in the level of the hormone of thyroxin, which enters the blood in a limited amount. The brain is particularly sensitive to this hormone, and its deficiency affects thermoregulation.

Cardiovascular problems, diabetes and hypothyroidism can provoke a metabolic syndrome, among the non-specific signs of which doctors have low body temperature and sweating, dizziness and low body temperature.

In the symptomatology of adrenal insufficiency -  Addison's disease  - low body temperature and nausea with vomiting, hypotension, a drop in blood glucose level, etc. The pathogenesis of thermoregulation disorders in this disease is associated with a decrease in the production of cortisol, resulting in hypoglycemia, and the lack of sugar in blood, as already noted above, slows down metabolism.

Low body temperature in hepatitis can be explained by the fact that liver damage by hepatitis viruses disables hepatocytes, which provide chemical thermoregulation.

Oncologists noted a low body temperature with cancer. This phenomenon is especially common in malignant proliferation of leukocytes and their precursors in blood and bone marrow in patients with lymphocytic and myeloblastic leukemia and myelogenous leukemia, as well as with Hodgkin's lymphoma.

Consequences and complications

What is dangerous for low body temperature? The body needs energy to keep heat, and low body temperature does not allow this energy to be produced.

Body temperature below the norm is dangerous because conditions are violated to maintain the body's homeostasis and the normal functioning of not only many of its systems, but also every cell - due to the slowing down of chemical reactions and physiological processes.

The action of enzymes, hormones, neurotransmitters and other biochemical factors that ensure the work of internal organs, central and autonomic nervous system changes.

In this state, which is accompanied by an increase in the acidity of body fluids, both adults and children are more susceptible to any infections - due to a lack of an adequate immune response. While the response to therapy and the effect of medications, even the most effective, is declining.

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Diagnosis of diseases causing a decrease in temperature

To determine the causes of the violation of thermoregulation, diagnostics is carried out, including

Blood tests (general, biochemical, glucose, antibodies, sex and thyroid stimulating hormones, ACTH, cortisol, hepatitis viruses, etc.) and urine.

Instrumental diagnostics are used, including: electrocardiography, encephalography, x-ray or chest fluorography, ultrasound examination of the thyroid gland, adrenal cortex, liver. CT scan of the spinal cord or MRI of the brain may be required.

Considering a wide range of diseases and conditions in which temperature indicators can be lower than the physiological norm, differential diagnostics and the involvement of physicians of different specializations - from endocrinologists and neuropathologists - are necessary.

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What if the person has a low body temperature?

Everyone knows that there are many antipyretic drugs - to reduce the fever. Are there any drugs that can raise it?

Drugs that can raise the temperature after taking the medication are available (antihypertensive adrenomimetics, sulfonamides, histamine type I receptor blockers, etc.), but their direct purpose is not to increase the temperature indexes: the pyrogenic effect they have on the body is a side effect of them ...

So what should I take at a low body temperature? And how to raise a low body temperature? Unquestionably, vitamins play an important role in enhancing the body's defenses, but they can not affect thermoregulation. Unable to do this and various immunomodulating agents.

Low body temperature is one of those symptoms, the treatment of which is possible only with the therapeutic effect on the diseases that cause it. Doctors prescribe drugs and apply methods for each case: for infectious pneumonia, antibiotics are needed, for diabetes - hypoglycemic drugs and diet, for oncology - radiation therapy and cytostatics.

Read more about the methods of treatment for some of them:

Physiotherapeutic treatment

To improve the condition of patients - depending on the specific diagnosis - physiotherapy (in the form of various hardware procedures), therapeutic massage and physical education are directed.

See -  Physiotherapy with vegetative-vascular dystonia

Alternative treatment -  Treatment of thyroid diseases by alternative means

Herbal treatment -  Herbs that enhance immunity, as well as -  Herbs that increase hemoglobin

Prevention

It is almost impossible to prevent a decrease in the temperature indices during a particular disease. This also applies to a decrease in the production of hormones, and genetic pathologies of the hypothalamus, and the development of brain tumors, and leukemia. Doctors traditionally advise to strengthen immunity, eat normally and lead a healthy lifestyle. Also, physical activity and movement are important to activate metabolism, since most of the heat energy is produced by our muscles.

And how to prevent anemia, more in the article - How iron deficiency anemia is  prevented

Forecast

A single forecast as to how low body temperature will affect health status can not be the same.

However, it should be borne in mind that normal temperature is important for the body, and its internal mechanisms can overcome most of the unfavorable factors.

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