Learn about fever, why is it caused and how to mitigate it

Fever is a sign for several conditions, learn how does it appear on the human body, what illnesses it is associated with, and ways to combat it.

Fever is a sign that will give many symptoms, the importance of fever is that it is a sign that we can objectify, we can evidence it, see it, quantify it in patients, it is not a sign that is exposed to emotional variations.

So what is fever useful for? It is useful to determine the severity, the evolution of the condition and to see if there is a response to treatment.

So the first thing we have to see is if the temperature is normal at the central level, above 37.5°C we are already talking about fever.

Definition:

Increase in body temperature in response to an elevation of the hypothalamic thermoregulatory center.

Over 37.5° of axillary temperature we will speak of fever.

Epidemiology:

It is a symptom/sign of very high prevalence that constitutes one of the main reasons for consultation in the general population, i.e. 80% of the patients may come with fever out of 100%.

This is where the pathophysiology comes in, we have to learn and differentiate two things: the increase in fever can be due to a natural cause, since we normally have periods of thermal rise (when we eat food, or when we exercise), this is the capacity of our body to know how to regulate and achieve that the body cools down normally, but these conditions cannot be considered as fever, the condition that we are going to say is fever is when it is secondary to a pathology or a disease (bacteria, virus, fungus), so that of the 100 cases that come with fever, only 80 will be considered as a disease.

Its potential “severity” can be influenced by the possible ACUTE pathologies, so when there are thermal rises we really have to think about all organs, all organs can be producing fever either naturally or pathologically, for example: at CNS level (bacterial meningitis, miliary tuberculosis) at heart level (pericarditis) at the level of the lungs (pneumonia, bronchitis, tuberculosis) in the liver (hepatitis) in the pancreas (acute pancreatitis), etc.

The thyroid is an important organ because it is involved in the metabolism of the body, it is the only organ that by an overproduction of hormones can give us a hyperthermia, it is one of the main causes of fever of unknown origin.

Of all the organs the thyroid and the brain can give us persistent fever that can take the fever to 40 ° C, these patients are bathed with ice because being a dysfunction the use of antipyretics does not make them any effect, the only way to lower it is with physical means. Hence we have to differentiate between fever, hyperthermia and hypothermia.                                                     

Fever: It is a rise in temperature but it is characterized by a return to normality, it can reach 38 °C and with antipyretics or physical means the fever tends to go down.

Hyperthermia: It damages neurons, we cannot allow this to happen, it is observed more in ICU (Intensive Care Unit), it often happens in neurological patients, where it is important to know the 6 H (Hyperthermia, Hypoglycemia, Hypernatremia, Hyponatremia, Hypervolemia, Hypovolemia), hyperthermia damages neurons by destroying myelin.

Hypothermia: It is a mechanism that lately is widely used as a treatment in cardiac surgeries, since the heart is stopped with ice, by the slogan “cold heart protects the brain” has been seen that by putting patients in hypothermia, all the injury mechanism that can occur in the brain is slowed and improves the dysfunction that causes fever, fever is lowered to 32 ° C, slows brain metabolism, decreases apoptosis, decreases the NaK pumps and Ca + pumps.

Classification of fever:

According to its duration:

1. Acute (infections).- is a sudden process given by flu, pneumonia, gastroenteritis, etc.

2. Prolonged (more than 15 days), are chronic diseases, such as thyroid pathologies hyperthyroidism, arthritis, tuberculosis, etc.

3. Fever of Unknown Origin, last more than 3 weeks. There are people where the diagnosis is very complicated, such as tuberculosis, HIV, autoimmune diseases, etc.

According to their pattern:

1. Intermittent (Hectic or septic), he thermal rise occurs and then returns to a normal pattern, is two or three hours with fever and then returns to 37 ° C Examples: bacterial abscesses, miliary tuberculosis, lymphomas, etc..

2. Continuous (sustained), the thermal rise does not have to return to its normal value despite physical or antipyretic means in this case it is put in the indications, to administer antipyretics if the temperature is higher than 37.5 ° C or 38 ° C, It does not present variations greater than 0.6 ° C per day. Examples: pneumococcal pneumonia

3. Remitting fever (continuous): During its evolution, normal values are never reached during each day of fever, this is the one that presents as hyperthermia that reaches values of 39 to 40 °C. Most febrile illnesses present themselves in this way.

4. Recurrent (continuous) is the chronic fever is in Dromedary, this type of fever occurs in malaria, which gives this type of fever, are continuous and recurrent.

What symptoms can fever cause?

General malaise, decay, cold sensation that may alternate with heat sensation. There may also be headache, palpitations, thirst, anorexia, drowsiness, skin hyperesthesia, polyalgia and photophobia.

Thirst is caused by dehydration and is compensated by sweating, by breathing we eliminate vapors.

The palpitation is because there is a decrease in oxygen consumption and the heart circulates the blood faster to compensate for the lack of oxygen, also by metabolism by the formation of adrenaline by stress.

As treatment: Hydration, it is necessary to give them liquids, physical means and then antipyretics.

Signs:

– Feverish facies (flushing, sweaty skin, bright eyes).

– will depend on the stage of evolution of the fever, since initially there will be pallor and cold skin especially in extremities.

– Axillary temperature at rest, over 37.5°C, in children rectal temperature will be taken.

– tachycardia and polypnea (increase of the heart rate by 10 beats per minute and of the respiratory rate by 5 cycles per minute, for each degree of increase of the T°).

– Signs may also include

– Tasteful tongue,

– dryness of skin and mucous membranes.

– The hyperdynamic condition may determine the presence of an ejection systolic murmur (II-III/VI) in the apex, where the heart starts beating hard and the murmur appears.

Explosive vomiting with fever is important because the brain may be affected. Persistent fever with tachycardia, we would be talking about hyperthyroidism.

Please examine:

– General condition of the patient

– confirm febrile rise

– Vital signs

– hydration level

– search for the probable disease of origin by means of a complete general and segmental physical examination.