Causes of subfebrile fever

Every person knows that if the thermometer shows elevated temperature readings, then an inflammatory process is taking place in the human body. It turns out that this is not entirely true and high temperature can be caused not only by inflammation, the causes of subfebrile temperature can have a completely different genesis.

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Causes of subfebrile temperature in women

A woman's body is a rather complex structure of various interrelations. Throughout her life, her body grows, develops, and certain transformations occur. Hormonal levels also change. The causes of subfebrile temperature in women are different, some of them are the same for both women and men, but, naturally, there are also purely individual ones.

• Once you reach puberty, your hormone balance can change depending on the phase of your menstrual cycle. So it is normal for your temperature to rise just before your period.
• Pregnancy period. Temperature fluctuations are also possible during the period when a woman is preparing to become a mother, carrying her baby. This is also associated with hormonal changes in the body.
• A respiratory viral infection can cause such a symptom. After the acute period of the disease has passed, the presence of subfebrile temperature indicates that the inflammatory process has not yet been completely stopped and the fight against the virus is not complete. Therefore, even if the symptoms of ARVI have gone away, it is imperative to continue treatment. In this situation, it would be a good idea to make an appointment with a specialist (an otolaryngologist). If there are no symptoms, the doctor may prescribe an examination, for example, a throat swab test for the microflora present. This will help determine the extent of the pathological invasion. With a normal course of an acute respiratory disease, fever can persist for up to five days, if there is no decrease, then the disease has continued in the form of complications. Additional diagnostics and adequate therapeutic treatment are necessary.
• Persistent subfebrile temperature is a defect of the hypothalamus and pituitary gland. These areas of the human brain are responsible for fluctuations in body temperature. Unreasonable subfebrile temperature can indicate that the functioning of these areas is disrupted and differs from the norm. If this cause of the deviation is suspected, the specialist prescribes magnetic resonance imaging (MRI) to the patient. One of the reasons for their failure can be a developing tumor.
• Another reason for the appearance of the symptoms under consideration may be a severe pathology of the thermoregulation organs. A deep subject examination and treatment are necessary, and in some cases, lifelong supportive therapy.
• Severe stress can also cause the development of subfebrile pathology.
• Dental diseases, such as caries.
• As medical statistics show, the modern population, especially in large cities and metropolitan areas, suffers from neuroses to varying degrees. Nervous stress affects not only the psyche of people, but also the entire body suffers from strong emotional overexcitement. Sometimes the nature of some manifestations is quite difficult to determine. For example, a person complains of discomfort in the throat and begins to treat it with antiviral drugs - the result is zero, since the cause of the sore throat may be a nervous shock. Therefore, if against the background of subfebrile temperature there is irritability, a sharp change in mood, a feeling of anxiety and sleep disturbance, then these are clear signs indicating that the fever may persist as a reaction of the body to neurosis.
• If the thermometer readings increase in the evening, vegetative-vascular dystonia (VVD) can provoke such a clinical picture. This diagnosis denotes a fairly wide range of diseases associated with the vascular system of the brain. But a more specific diagnosis can be obtained after a systematic examination.
• Subfebrile temperature is mainly caused by chronic infectious lesions of the ENT organs and the genitourinary system. If a person has, for example, cystitis or tonsillitis in their medical history, in the chronic stage of the course, then the risk of recurrent activation of pathogenic microorganisms increases significantly. Relapse provokes an exacerbation of the disease and an increase in temperature indicators.
• Subfebrile temperature may be a consequence of the recovery period after therapeutic treatment of pneumonia. But if X-ray and blood tests do not show any deviations from the norm, then there is no need to worry. Gradually everything will normalize and return to normal.

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Causes of subfebrile temperature in children

Every person knows from childhood that the normal human body temperature is 36.6. But doctors are not so categorical and allow the norm to be up to 37.0 o. But if a child's thermometer shows numbers from 37.0 to 38.0 o C for several days in a row, then this fact begins to seriously worry the parents. It is interesting that such indicators can be maintained in the baby for a month, while not accompanied by other negative symptoms. During this period, the child feels absolutely normal and leads an active lifestyle.

If such a situation is observed for at least two weeks, doctors begin to talk about subfebrile condition - a medical situation in which the clinical picture is colored by a single symptom - and this is subfebrile temperature. You should not ignore such a reaction of the baby's body. After all, it indicates the presence of some kind of failure, which, it is desirable to quickly identify and take the necessary measures.

The causes of subfebrile temperature in children are different, but some of them can be voiced:

• Latent infectious lesions of internal organs.
• An allergic reaction of the baby’s body to any external irritants can also cause such a symptom.
• Increased activity of the thyroid gland, which produces excess enzymes, can also provoke an increase in temperature.
• The source of high temperature can be an invasion of protozoa, such as worms.
• Low levels of hemoglobin or red blood cells in a child's blood (anemia) are often the cause of temperature fluctuations.
• The symptom can also be caused by disruptions in metabolic processes, for example, in diabetes.
• Diseases affecting children's brain structures.
• A severe form of vitamin deficiency, especially when the baby’s body lacks vitamins such as C and the entire spectrum of group B.
• Congenital or post-birth malfunctions of the immune system.
• Thermoneurosis is a condition in which the body of a small patient experiences a disruption of natural thermoregulation, that is, the child's body produces more heat per day than it can use up. It is this excess that causes subfebrile temperature. Such a failure can occur due to disruptions in the endocrine system or the thermoregulatory center located in the brain.

It should be remembered that subfebrile temperature is not relieved by antipyretic drugs. And the problem is not even that it is useless and does not give any effect, but also that the protective forces of the small organism are weakened, worsening its ability to resist and fight the disease.

In such a situation, parents are required to monitor the baby's body temperature for some time; it would be a good idea to record these indicators in a notebook. This approach will allow the specialist to better assess the situation. If the temperature remains high for several days in a row, then you cannot do without consulting a pediatrician.

The doctor will prescribe a general examination and after receiving the results will be able to give the necessary recommendations or prescribe treatment therapy. Doctors believe that it is necessary to treat this pathology. After all, any deviation from the natural functioning of the child's body is stress for it.

In addition to medication, if necessary, parents can help their child by organizing a proper daily routine for him, which will include moderate exercise and adequate rest, including normal long sleep. Hardening the baby's body is not the last place - this will help to eliminate many health problems of the child. Physical training will also be beneficial for strengthening the body. You just need to adhere to the systematic implementation of such procedures, otherwise you may not see the desired result. Hypnosis and acupuncture are practiced in such a clinical picture.

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Causes of prolonged subfebrile temperature

Subfebrile symptom is called thermometer readings within the range of 37 to 38 ˚C. Its long-term manifestation is a fairly common complaint, with which patients seek advice from a specialist. The causes of long-term subfebrile temperature can be different, to establish them, the patient must undergo a full examination.

Quite often, subfebrile condition is observed in young women against the background of increased fatigue, exhaustion of the body by all sorts of diets, weakening or loss of ability for prolonged physical or mental work. This fact is explained by the physiological individuality of the female body. It is women who show a high level of infectious damage to the urogenital system, and it is the female body that is subject to multiple psycho-vegetative disorders.

It should also be understood that a long-lasting fever is very rarely caused by an organic disease. Mostly, this symptomatology reflects classical vegetative dysfunction - the disease is caused by a symptom complex of disorders of vegetative, sensorimotor and psychoemotional activity.

The sources causing the prolonged manifestation of the symptom in question are divided into two groups: non-infectious and infectious pathologies.

Such infectious diseases include:

• Tuberculosis. When a high temperature appears and persists for a long period of time, the first thing doctors do is to exclude such a terrible disease as tuberculosis from the list of possible causes of the pathological manifestation. This is not always easy to do. When determining the anamnesis, the doctor necessarily finds out whether the patient has had contact with a patient suffering from an open form of tuberculosis.
• If the patient has a history of treated tuberculosis. This disease is dangerous because it shows a high percentage of relapses. This may be a poorly treated disease that was carried out over the past three months.

In the presence of one of the forms of tuberculosis, in addition to prolonged subfebrile temperature, additional symptoms can be observed:

• General intoxication of the patient's body.
• Rapid fatigue and weakness.
• Increased activity of sweat glands.
• Decreased appetite.
• Weight loss.
• A cough that lasts more than three weeks is a sign of pulmonary tuberculosis. This may also include shortness of breath, coughing up blood, and pain in the chest area.
• Complaints about the normal functioning of the damaged organ.
• Focal infection. Many doctors say that one of the reasons for subfebrile temperature is the presence of a constant source of infection in the patient's body (sinusitis, adnexitis, tonsillitis, etc.), although in most cases these diseases are not accompanied by high temperatures. The involvement of this pathology in the phenomenon under consideration can only be proven in practice: by sanitizing the affected area, we get a decrease in temperature.
• Chronic toxoplasmosis. About 90% of patients suffering from this disease have the symptom we are considering in their symptomatic set.
• Chronic brucellosis shows a similar picture.
• Subfebrile temperature is a constant companion of such a disease as acute rheumatic fever.
• The symptom in question may be a consequence of a past infectious disease, which doctors call a "temperature tail." Whooping cough is an example. After the patient ceases to be contagious, his subcortex continues to send signals to cough, and a similar mechanism is triggered here. The result is the so-called post-viral asthenia syndrome - a developing psychopathological disorder. In such a situation, tests show the norm, and the temperature returns to normal values on its own, sometimes within a couple of months, and sometimes this can stretch out for up to six months. Although this cannot be stated unequivocally. Everything depends on the specific disease and the severity of its manifestation.

Non-infectious diseases that can cause prolonged subfebrile temperature include:

• Thyrotoxicosis is a disease of somatic nature. Its occurrence is caused by a high concentration of thyroid hormones in the patient's blood plasma.
• For some people, subfebrile temperature is an individual physiological norm.
• The symptom in question may be caused by physical activity, such as intense exercise.
• A high temperature can appear due to emotional overload.
• Due to its individual characteristics, the body is able to react to food intake with such symptoms.
• A rise in temperature can be caused by prolonged exposure to a hot and stuffy room.
• Pregnancy can cause this symptom. It is a rare manifestation, but it can manifest itself during the first three to four months from the moment of conception.
• Premenstrual period in some representatives of the fairer sex.
• As long-term medical monitoring shows, when measuring body temperature in different armpits, the measurement results may differ by 0.1-0.3 ˚С. For some reason, the left side shows higher readings.
• Due to the individuality of the body, the thermometer may register constant high temperatures as a reflex reaction of the body to the measurement procedure itself. This only applies to axillary indicators. When measuring this indicator in the oral cavity and through the anus, such deviations were not detected.

The symptoms we are interested in can be provoked by reasons related to the psycho-vegetative area of the human body:

• Vegetative neurosis is a disease associated with organic changes in the tissues of the autonomic nervous system, the result of which is a disruption of their normal functioning.
• Thermoneurosis is an increase in body temperature, the etiology of which is the neurasthenic nature of the pathology. High rates in this disease can persist for more than one year.
• The patient's medical history includes traumatic brain injury.
• Violation of structural and functional homeostasis, metabolism and functions in a pathological process affecting the endocrine system.
• Psycho-emotional overload.
• Seasonal or permanent allergies.

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Causes of constant subfebrile temperature

The constant presence of elevated body temperature indicators in the ranges above 37.0 °C to 38.0 °C, is recorded for a long time: from a couple of weeks to several months, or even more than one year, such a clinical picture falls under the diagnosis - subfebrile temperature. To combat the problem, you need to know its source. The causes of constant subfebrile temperature are somewhat diverse, and the effectiveness of the fight against this pathology depends on whether the primary source is established or not.

• One of the reasons for a constantly present high temperature may be the individual characteristics of the human body.
• Internal sluggish inflammatory processes of various etiologies can provoke constant high readings on the thermometer.
• A failure in the body's thermal regulation process can be a consequence of a disease of the nervous system (organic in nature) affecting the brain stem structure.
• A non-specific focal infection that has become chronic, for example, pancreatitis, sinusitis, cholecystitis, and others.
• Chronic diseases based on inflammation, such as pneumonia.
• Latent sexually transmitted infections, such as syphilis, chlamydiasis, HIV infection.
• Open or latent form of tuberculosis.
• A persistently elevated temperature may be observed in the case of invasive infection by helminths or other protozoan parasites.
• In modern conditions, doctors often diagnose a latent form of sepsis.
• Malignant tumor.
• Pathological changes associated with a violation of the immune reactions of the human body. This may be rheumatoid arthritis, enteritis, nonspecific ulcerative colitis, allergic reaction to medications.
• Subfebrile temperature can be observed in women in the premenopausal period.
• Endocrine pathologies: thyrotoxicosis, pheochromacytoma.
• Thermoneurosis is a persistent disorder of heat exchange resulting from functional damage to the thermoreflex center, which occurs with autonomic dysfunction in children, adolescents and young women.

The problem in determining the functional causes of subfebrile fever is that most patients have a history of chronic infection.

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Causes of subfebrile temperature in a teenager

The most common causes of subfebrile temperature in a teenager are similar to the above-listed sources. The most common source of a disease that can provoke high temperature indicators observed for a long time is an infectious lesion (of various etiologies) of the patient's body. It would seem that the acute respiratory viral infection (ARVI), familiar to many, in most cases, in addition to general weakness, headache, pain symptoms in the joints, rhinitis and cough, is also accompanied by subfebrile temperature.

Some infectious diseases (for example, chickenpox, rubella) in infancy occur practically without fever or it takes on slightly elevated values, whereas in adolescence these pathologies proceed more difficultly, and body temperature indicators are recorded at higher numbers.

In case of a prolonged inflammatory process, the main symptoms often lose their severity and become habitual. The only criterion signaling the presence of an internal problem is subfebrile temperature that does not go away for a long time. In this situation, it can be quite difficult to determine the root cause of the pathology.

The foci of infectious lesions in the adolescent's body can be:

• Diseases of the ENT organs, such as:
  • Sinusitis.
  • Pharyngitis.
  • Rhinitis.
  • Tonsillitis.
  • Laryngitis.
  • Otitis.
  • And other diseases.
• Dental caries or periodontitis.
• Pathological lesions of the digestive tract:
  • Colitis (inflammatory process of the intestinal mucosa).
  • Cholecystitis (inflammatory disease of the gallbladder).
  • Gastritis (inflammation of the mucous membrane of the stomach wall).
  • Pancreatitis (inflammation of the pancreas).
  • Duodenitis (inflammation of the duodenum).
  • And others.
• Infectious and inflammatory lesions of the urinary tract:
  • Cystitis.
  • Urethritis.
  • Pyelonephritis.
  • Other diseases affecting this system.
• Inflammatory diseases affecting the genitals of a teenager.
• Abscesses formed at injection sites.
• Pathological changes of endocrine genesis.

To make a correct diagnosis and find the cause of subfebrile temperature, the attending physician usually prescribes a general blood and urine test. The results of their study clearly show the presence or absence of an inflammatory process in the teenager's body. This conclusion is made on the basis of the leukocyte formula, as well as the ESR (erythrocyte sedimentation rate).

Consultations with more specialized specialists are scheduled: dentist, gynecologist, gastroenterologist, otolaryngologist, surgeon, and, if necessary, neurologist.

To confirm or refute their suspicions, the specialist prescribes additional examination. This may be an ultrasound examination, computed tomography, radiography and other diagnostic methods.

If the disease is diagnosed, it is necessary to undergo full drug therapy. Chronic infectious lesions are especially difficult to treat.

Quite rarely, but the cause of subfebrile temperature can be:

• Toxoplasmosis, the causative agent of which is the simplest intracellular parasite - Toxoplasma gondii, the main source of which is domestic animals or poorly cooked meat.
• HIV infection.
• Brucellosis is a zoonotic infection. It is mainly capable of affecting a teenager who actively helps his parents in caring for pets. This disease is quite dangerous, leads to intractable motor and psychological disorders, and the probability of a fatal outcome is very high.
• Parasitic infections caused by helminths, pinworms, roundworms and other parasites.
• Tuberculosis. As sad as it may sound, today this disease has moved from the category of social to pathology, which can affect even small children, and increasingly affects the body of adolescents. Therefore, the annual Mantoux test, carried out in schools, makes it possible to promptly identify and treat the disease. If the lesion affects several organs, then it can be very difficult to determine the cause of subfebrile temperature using only chest X-ray. At the current stage of medical development, diagnostics of extrapulmonary forms still remains quite difficult.

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Causes of subfebrile temperature in the evening

Quite often people accidentally learn about the presence of subfebrile temperature, this is due to the fact that very often such a temperature anomaly does not manifest itself with accompanying pathological symptoms. But before you panic, you should strictly follow the instructions for measuring the temperature correctly. You need to know that the measurement in the armpit must be carried out, holding the thermometer for 5 - 10 minutes. When measuring temperature indicators with more modern electronic devices, first, you must carefully read the instructions attached to the device and follow all its requirements. Mostly, the time interval for measuring is also 5 - 10 minutes.

The end of the measurement time should be determined by the sound signal only if the measurement is taken through the anus. It should not be forgotten that the temperature measured in the rectum is somewhat higher than with a similar measurement in the armpit area.

It is worth knowing that the reasons for subfebrile temperature in the evening can be quite banal. The human body is organized in such a way that in the interval from four to six o'clock in the morning and from four to eight o'clock in the evening, a physiologically justified increase in body temperature readings is observed. For many people, such increases fall into the subfebrile zone. To determine that such a picture is an individual feature of your body, you should simply take fixed measurements every three to four hours during the daytime, as well as at least once during the night. Such manipulations must be done for several weeks. The results obtained should be summarized in a table, so it will be easier to analyze the results of the measurements.

It is almost impossible to determine the cause of a pathological symptom on your own. And if subfebrile temperature is detected during measurement, you should consult your local doctor. He is professionally able to assess the situation and, if necessary, write out a referral for consultation with a more specialized specialist. At the same time, medical statistics show that for 2% of the world's population, a constant subfebrile temperature, especially in the evening, is the norm.

It should not be forgotten that when measuring body temperature under different armpits, the measurement results in most cases differ by 0.1-0.3 ˚С. The left side generally gives higher readings.

But the reason for elevated thermometer readings in the evening can be an untreated infection, a sluggish inflammatory process that has become chronic, stressful situations, as well as other pathological disorders. But only a qualified specialist can establish the cause and source of the disease. He is also able to prescribe effective relief therapy or, if the cause is not related to pathologies, give the necessary recommendations.

If a person does not feel any pain, and the thermometer shows a slightly elevated temperature, many people do not attach much importance to such a picture. But after reading this article, we can conclude that ignoring this symptomatology can lead to irreversible pathological changes in the human body, because the causes of subfebrile temperature are quite diverse and the source of the symptom in question can be a fairly serious disease. No one in this article calls for panic right away, but it will not be superfluous to undergo a full examination. After all, the earlier the disease is diagnosed and treated, the greater the likelihood of a favorable outcome, and the likelihood of various complications is minimized.

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