High body temperature is a violation of thermoregulation, in which the temperature rises above 37 °C. The symptom is accompanied by headaches, muscle aches, sharp weakness, malaise. Fever occurs more often with infectious diseases, but fever may also have a non-infectious origin — endocrine and autoimmune diseases, tumors. To find out the cause of hyperthermia, extended laboratory tests and imaging methods are carried out. Antipyretics and physical methods of cooling usually help to bring down the temperature quickly.
Temperature indicators change in absolutely healthy people throughout the day, in the morning the values are a couple of tenths of a degree lower than in the evening. An increase of more than 37 °C when measured in the armpit indicates a pathology of thermoregulation. Body temperature rises gradually more often. At first, prodromal symptoms appear — headache, body aches, general malaise, and later – a subjective feeling of cold, muscle trembling. When the indicators increase more than 38 °C, the chills are replaced by a strong feeling of heat, the skin is hot to the touch, bright red blush on the cheeks.
The general condition of patients worsens, they refuse to eat. Lips dry out and crack, and severe dry mouth worries. The period of persistently elevated temperature lasts from several days to a month or more, depending on the cause of the fever. Normalization of thermoregulation processes can be abrupt — with pronounced weakness, profuse sweats and hypotension, or gradual when the general condition remains satisfactory. The child’s temperature rises faster, up to 39-40 °C in a few hours.
Fever is always combined with other symptoms that correspond to the underlying pathology. Abdominal pain and dyspeptic disorders, signs of acute respiratory viral infections are most often observed. At a temperature of 37 °C and above in an adult, which lasts for more than 2 days, it is necessary to consult a doctor. When a child has a fever, medical care is required already on the first day of fever, since thermoregulation mechanisms are not developed in childhood, fever is more severe.
According to the etiological factor, fever can be infectious – caused by bacteria, viruses and fungi or non-infectious – with damage to internal organs, tumors, allergic reactions. By duration, high body temperature is classified into ephemeral (up to 3 days), acute (from 3 days to 2 weeks), subacute (2-6 weeks) and chronic (lasting over 1.5 months). In clinical practice, the classification of fever is more often used, taking into account the level of pathologically elevated temperature, according to which there is:
- Subfebrile body temperature. Temperature values are in the range of 37-38 degrees, accompanied by weakness, weakness, decreased ability to work. It is often found in chronic sluggish inflammatory processes in the body — some infections with a latent period, endocrine diseases.
- Febrile body temperature. Numerical values from 38° to 39 °C. Its appearance indicates an active inflammatory process that triggers the internal causes of fever: the mechanisms of the immune system, massive production of endogenous pyrogens. It is observed in many infectious and somatic pathologies.
- High (pyretic) body temperature. Severe violation of thermoregulation with fever 39-41 °C. There is a sharp deterioration in the condition, severe dehydration, nausea and vomiting. It is an urgent condition in pediatrics, because children sometimes develop seizures.
- Hyperpyretic body temperature. An extremely serious condition when the temperature indicators exceed 41 degrees. Indicates a complete breakdown of the mechanisms of central thermoregulation. In addition to the usual signs of fever, there are disturbances of consciousness with delusions and hallucinations. The condition requires emergency care.
Doctors evaluate fever by fluctuations in indicators during the day — the so-called temperature curve. The constant temperature is characterized by fluctuations within 1 degree, with a relaxing fever, the indicators change by 1-2 °C, but do not reach normal temperature. With the hectic form, which is caused by purulent and septic processes, temperature fluctuations are 3-5 °C during the day. The rarer types of temperature curve include intermittent, recurrent and undulating.
Subfebrile body temperature
An increase in temperature of more than 37 degrees on the skin or more than 37.8 ° C when determining the parameters in the rectum is observed with insignificant production of cytokines and pyrogens, which affect the thermoregulation center in the hypothalamus. The condition is accompanied by general malaise, but working capacity is often preserved. Subfebrile body temperature is caused by such reasons as:
- Emotional reactions: prolonged stress, neurosis and neurosis-like states, hysteria.
- Hormonal changes in women: the first trimester of pregnancy, menopause.
- Respiratory diseases: colds, acute respiratory infections, simple bronchitis and interstitial pneumonia.
- Focal inflammation: chronic tonsillitis, sinusitis.
- Chronic bacterial infections: tuberculosis, brucellosis, Lyme disease.
- Viral processes: acute hepatitis, herpes simplex and shingles, cytomegalovirus.
- Childhood infections: measles, rubella.
- The temperature “tail” of infectious diseases.
- Helminthiasis: giardiasis, amoebiasis, opisthorchiasis.
- Intestinal pathologies: ulcerative colitis, Crohn’s disease, Whipple’s disease.
- Autoimmune processes: systemic lupus erythematosus, scleroderma and dermatomyositis, rheumatoid arthritis.
- Endocrine pathology: the initial stage of thyrotoxicosis, Addison’s disease.
- Tumors: lymphogranulomatosis, acute and chronic leukemia.
- HIV infection.
- Iatrogenic factors: postoperative period, reaction to blood transfusion or vaccination.
- Complications of pharmacotherapy: taking antibiotics, psychotropic drugs, atropine.
- Rare causes: chronic sepsis, allergic reactions.
Febrile body temperature
If the body temperature is constantly elevated to 38 degrees or more, this indicates an acute course of the disease. Patients report severe headaches and muscle pains, weakness, drowsiness. At the same time, appetite is reduced, and the feeling of thirst increases due to massive losses of water with sweat and breathing. Common causes for which febrile fever develops:
- Acute respiratory pathologies: influenza, adenovirus and rhinovirus infections, ARVI.
- Infectious diseases: typhoid and typhus, malaria, meningococcal meningitis.
- Intestinal infections: salmonellosis, dysentery, escherichiosis, etc.
- ENT diseases: sinusitis (sinusitis, frontitis), angina, otitis.
- Lesion of the lower respiratory tract: purulent bronchitis and bronchiolitis, exudative pleurisy, focal and croup pneumonia.
- Purulent foci: external (boils, carbuncle, suppuration of wounds) and internal (liver abscess, intestines, empyema of the pleura).
- Acute abdominal syndrome: appendicitis, cholecystitis, mesadenitis.
- Heart diseases: bacterial endocarditis, acute rheumatic fever, Liebman-Sachs endocarditis.
- Bone and joint damage: hematogenic and traumatic osteomyelitis, septic arthritis, sarcomas.
- Pathology of the genitourinary system: acute pyelonephritis, apostematous nephritis, renal colic.
- Overheating of the body: heat and sunstroke, anhidrosis, wearing clothes that do not correspond to the weather.
- Fever of unknown origin.
- Rare causes: prion infections (Creutzfeldt-Jakob disease, kuru, fatal familial insomnia), vascular collagenosis.
The examination of patients with fever is carried out by a general practitioner. The scope of diagnostic measures depends on the clinical picture and the presence of additional symptoms, if there are obvious signs of damage to a certain system, its targeted diagnosis is carried out. In the case of a prolonged fever of unknown cause, the examination is performed according to a standard algorithm, which includes advanced laboratory methods and instrumental visualization. The most informative studies:
- Blood test. In the general analysis, attention is paid to signs of the inflammatory process (leukocytosis, increased ESR). The levels of acute-phase proteins and antinuclear antibodies are measured to exclude autoimmune processes. In the period of acute inflammation, the procalcitonin test is informative. To assess the function of the heart, an analysis is made for antistreptolysin, troponin.
- Hemoculture. Blood sampling is carried out in the period of the most elevated temperature, at least 3 times. Seeding of the material is carried out on selective nutrient media, in the presence of a large number of bacterial colonies, septicemia is diagnosed. Additionally, blood is examined using ELISA, RIF – express methods to detect antibodies and antigens of pathogens.
- Bacteriological studies. In addition to blood, fecal and urine samples, sputum are used to isolate pathogens. If neurological symptoms are detected at an elevated temperature, cerebrospinal fluid is taken. After determining the colonies of pathogenic microorganisms, a test for sensitivity to antibacterial drugs is performed.
- Radiography. With prolonged retention of elevated temperature, chest X-ray are performed in two projections, on which areas of darkening, cavities with a horizontal fluid level, deformation of the bronchial tree can be detected. An overview radiography of the abdominal cavity helps to exclude abscesses, large inflammatory conglomerates and perforations of the hollow organ.
- Ultrasound examination. To clarify the cause of febrile fever, echocardiography is performed, during which signs of infectious endocarditis, valve vegetation, pathology of large arteries are determined. To exclude endocrine disorders, an ultrasound of the thyroid gland and parathyroid glands, adrenal glands is performed.
- Highly specific visualization methods. If the cause of the elevated temperature cannot be established by standard methods, scintigraphy of the whole body with gallium is shown, which allows to identify chronic abscesses, volumetric neoplasms. Osteomyelitis is confirmed by scintigraphy of bones with technetium. If meningitis is suspected, CT or brain MRI is recommended.
Help before diagnosis
With elevated subfebrile temperature, which lasts less than 2 days, specific treatment is not required. The long duration of symptoms indicates the presence of a pathological process, which is an indication for seeking medical help. Before determining the cause of fever, the patient should be provided with plenty of warm drink. Apply physical methods of cooling – wiping, cold compresses. To drink antipyretics to bring down the temperature, adults are recommended when the thermometer is more than 38.5 ° C, children are given antipyretics at a temperature elevated above 38 degrees.
Medical tactics treatment of high body temperature depend on the cause of the symptoms and the general condition of the patient. With high fever, temperature measurements in the hospital are carried out every 2-3 hours to assess the dynamics. In children, a violation of thermoregulation is sometimes accompanied by convulsions, therefore, when an increased febrile temperature is detected, they are immediately given antipyretic medications. An essential condition is adequate etiotropic and pathogenetic therapy, against which thermometry indicators normalize. For therapeutic purposes , they use:
- Antibiotics. Medications are selected empirically, the treatment regimen is adjusted after receiving the results of bakposev. For massive purulent processes, combinations of 2 or 3 drugs are recommended, which are administered parenterally in high therapeutic doses.
- Antiviral agents. In case of influenza, specific medications are indicated that block the reproduction of the virus and accelerate recovery. For the treatment of viral hepatitis, drugs have been developed that reduce the viral load and alleviate the general condition.
- Anti-inflammatory drugs. Nonsteroidal drugs block the synthesis of prostaglandins and cytokines acting on the thermoregulatory center, reduce the activity of the inflammatory process. NSAIDs with powerful antipyretic properties are used.
- Glucocorticoids. They are prescribed for severe systemic autoimmune or allergic reactions that do not respond to other therapy. They are used with caution in infections, since adrenal hormones suppress the activity of the immune system.
- Infusion solutions. At temperatures above 38 ° C and in a serious condition of the patient, rehydration and detoxification therapy are required. Salt solutions containing the most important electrolytes are poured in. Treatment is supplemented with diuretics.
- Vitamins. In sluggish processes, ascorbic acid and vitamins of group B are used to stimulate immunity. Metabolic drugs that improve metabolic processes in cells and have a tonic effect are effective. The funds are combined with antioxidants.
If large abscesses or foci of osteomyelitis are detected, they must be drained and the resulting cavities washed with antiseptic solutions. In diseases manifested by an “acute abdomen”, cavity operations with wide access are shown to remove altered areas of the intestine with subsequent sanitation of the abdominal cavity. In case of malignant tumors, radical surgical interventions are performed (removal of the formation together with the surrounding fiber and regional lymph nodes), combined with radiation exposure and chemotherapy.