Body temperature
We talk about fever when the body temperature rises above normal values.
It is very important for our body to maintain a relatively constant temperature internally, since in this way the various metabolic processes can take place at an optimal speed.
In particular, when waking up the lowest temperatures are recorded, while in the late afternoon these values can reach and exceed 37 ° Celsius. The fluctuation of body temperature during the day causes the athlete to reach his maximum performance level at around 6 pm. In fact, a temperature slightly higher than the norm improves the propagation speed of nerve stimuli and increases the metabolism facilitating energy production.
There are also many other factors such as the state of health, the presence of particular pathologies, digestion and physical activity that contribute to feeding these small thermal variations.
In light of all these elements it is easy to understand how in many cases the border between normality and fever is very thin.
For example, a temperature of 37.5 ° C recorded in the morning probably indicates a feverish state. Different discourse if this value is recorded towards evening in a woman in full ovulation (in this period of the menstrual cycle the body temperature is in fact higher than the norm of half a degree).
Measure the Fever
The temperature varies slightly in the various parts of the human body. In the clinic it is measured at one of the following points: oral cavity, armpit or rectum.
The value measured in the rectal area approaches with greater precision the real internal temperature (about 37 ° C ± 0.5 ° C). The axillary temperature is instead lower than the central one (36, 6 ° C ± 0, 5 ° C), as well as the sublingual one which is lower by about 0, 2-0, 5 ° C.
The most reliable temperature would, in any case, be the lower esophageal one.
Read the discussion: How to measure fever »
Causes
Fever itself is not a pathological condition but a symptom that arises in response to a particular disease.
Many pathogens are in fact able to influence the thermoregulatory center of the hypothalamus by moving it to a higher than normal temperature.
This real control center located in our brain is in fact sensitive to particular peptides called cytokines, which are secreted both by bacteria and viruses (exogenous pyrogens), and by cells of the immune system appointed to fight them (endogenous pyrogens).
Cytokines also have a painful action and cause disgust, nausea and general malaise. All this explains the association of fever with classic symptoms such as headache and
Since most pathogenic microbes are killed at a temperature close to 40 ° C, fever is a valuable defense for our body.
The hypothalamus is able to increase body temperature by controlling the functions of many organs and tissues.
Among the many weapons that our body has at its disposal to increase the amount of heat produced, while limiting dispersion, we recall vasoconstriction (reduction of the blood flow in the skin), increase in muscle tone (chills), and heart rate (tachycardia) and metabolic activity in general (increase in basal metabolism).
The increase in temperature is associated on the one hand with a reduction in the proliferation of pathogenic microorganisms and on the other hand with a significant increase in the activity of cells with immune function. Suffice it to say that an increase of half a degree compared to normal values is sufficient to considerably increase the response of B and T lymphocytes against pathogenic microorganisms.
If all these effects are well tolerated by an adult organism, in a child or in an elderly too intense immune responses can have harmful effects.
Fever should not be confused with heat stroke, a particularly serious episode in which the high temperature rise is not spontaneous but caused by an external event, such as getting into a car that has been left for hours under the scorching sun.
In addition to infection of bacterial or viral origin, fever can also arise as a secondary cause of specific diseases or derive from the use of some drugs.
Symptoms and Classification
CLASSIFICATION OF THE FEBRUARY:
- low-grade fever: if the fever does not exceed 38 ° C
- mild fever: temperature between 38-38.5 ° C
- moderate fever: 38.5-39 ° C
- high fever: 39-39.5 ° C
- hyperpyrexia: 39.5 ° -41 ° C
CONTINUED: the daily temperature fluctuations are lower than the centrigado degree and the fever persists over time
REMITTANT: the daily temperature fluctuations (at least two) are higher than the centigrade degree and never return to the basal values (characteristic of the majority of febrile diseases)
INTERMITTENT: fever rises and falls during the day to return to normal in the morning. If the temperature ranges are very high, this is called septic fever. Intermittent fever is characteristic of malignant neoplastic diseases.
RECURRENT: febrile episodes interspersed with more or less long periods of time when the body temperature returns to normal values (typical of some diseases such as malaria, brucellosis and borrelia infection).
SYMPTOMS:
- pallor (peripheral vasoconstriction)
- piloerezione (goose bumps)
- chills, feeling cold
- general malaise.
Care
How to cure fever
As we have seen, the feverish response is nothing but a powerful and effective means of defense. The increase in temperature can therefore be considered as a real medicine that our body has to defend itself from viral and bacterial infections.
Depriving the body of such important support by taking antipyretic drugs (capable of lowering body temperature) may in many cases have an adverse effect on what was hoped for.
For example the use of antibiotics can lower the immune system going to eliminate not only pathogenic bacteria but also useful ones. Furthermore, if the disease is caused by viruses, this class of drugs proves not only to be completely ineffective but even harmful because, for the reasons mentioned above, it lengthens healing times and favors the repetition of new infectious episodes.
Therefore, if the fever is not particularly high, the most effective therapy is the rest combined with the classic recommendations that include the consumption of easily digestible meals, the abundant intake of water and the abstention from smoking or alcohol.
To learn more, read: Diet and Fever »
It is also important to listen to the symptoms that our body sends us; if you feel cold it is better to cover yourself more, if on the contrary you feel a sensation of excessive heat it is good to gradually decrease the temperature of the environment.
In fact after a first phase in which the organism tries to retain the heat inside it to raise the temperature, a second phase follows in which this heat is dispersed outside to re-establish the thermal balance (sweating, vasodilation).
If the fever exceeds 39 ° C, especially if children and the elderly suffer from it, it is advisable to take medicines that can bring the body temperature below this value. Considering the numerous causes of fever origin, these medicines must be prescribed exclusively by a doctor after a thorough diagnostic examination in which the patient will take care to specify each symptom warned. If the temperature remains high for more than 3-4 days from the beginning of the therapy it is good to consult the doctor again to examine any complications.
To learn more, read: High Fever: What to Do? »
To learn more, read: How to Lower Fever "
To learn more, read: Antipyretics: Utilities and Precautions »
To learn more, read: Child Fever Medications »
