Body temperature often fluctuates a few times during the day. However, the body has the ability to maintain internal heat between 36°C and 37°C. When this limit is exceeded, fever appears, which is also called pyrexia.
Chances are, you’ve already thought that a fever is a disease. But in fact, it represents a sign that something is wrong with the body. It often does not indicate a serious health condition and even goes away on its own. However, if the temperature rises a lot, it is usually a symptom that deserves medical evaluation.
Next, check out details about the causes of fever, when you need treatment, and how to take your temperature properly.
Causes of fever
The brain has an area called the hypothalamus, which monitors the balance between production and loss of body heat. When the immune system responds to some kind of aggression, the hypothalamus raises its temperature to fight disease. This gives rise to fever, which is often a reaction of the body to fight invaders.
Among the causes of fever are:
- Viral (such as covid-19) or bacterial (such as meningitis or pneumonia) infections;
- heat exhaustion, sunburn, or excessive sun exposure (heat stroke);
- Rheumatoid arthritis;
- Some tumors;
- Use of medications, such as antibiotics and medication to treat high blood pressure or seizures
- Mild reaction from vaccines;
- Abuse of alcohol or some narcotics.
Symptoms accompanying fever
Depending on what is causing the fever, other signs may appear. The most frequent are:
- Sweating, ie excessive sweating;
- Chills and chills;
- Muscle aches;
- loss of appetite;
- General weakness.
In more severe cases, high fever causes mental confusion, delusions, and convulsions.
types of fever
Did you know that there are different ways a fever manifests itself? It is important to differentiate whether there is a pattern to assess symptom severity and even identify the cause. See details for each type.
Continuous fever: it is the one that is maintained, that is, it has few oscillations.
Remitting fever: when the temperature varies by more than 2°C.
Intermittent fever: the symptom comes and goes and the person has oscillations between high and normal temperatures.
Irregular fever: As the name implies, there are irregular temperature variations, alternating between high peaks and sharp drops.
Fever of unknown origin: high temperature on several occasions for at least three weeks and persists for no apparent reason.
Recurrent fever: when the individual has periods with fever and then long intervals without the symptom.
How to measure temperature?
The best way to diagnose fever is by taking your body temperature with a thermometer. The ideal is to place it in the armpit region, positioned properly and wait for the time to read. In the case of a mercury thermometer, the time varies from 2 to 10 minutes.
It is worth measuring the temperature at different times of the day and also noting the times and changes presented. It is worth noting that the feverish state starts to be considered from 37.8°C. Fever is considered mild up to 38.5°C and severe when it reaches or exceeds 39.5°C.
How is Fever Diagnosed and Treated?
The diagnosis of fever is made by measuring body temperature. To identify the causes, the doctor may order tests (blood, urine and image) after analyzing the person’s medical history.
At this point in the consultation, you will be asked if the individual has recently traveled, what vaccines he has had, if the fever is accompanied by other symptoms, or if he has had contact with someone who has recently been sick.
Generally, based on the collection of these data and exams, a diagnosis can be reached and a therapeutic plan developed. To reduce the fever, doctors prescribe medication to control the temperature, such as dipyrone or acetaminophen. This also helps to reduce discomforts, such as chills and malaise.
It is important to avoid self-medication, which can mask some disease symptoms and, in some cases, worsen the condition.
When is fever a concern?
It is important to note that, in cases of persistent fever for more than three days, the recommendation is to seek medical attention to assess the causes and start treatment as soon as possible.
In addition, it is worth keeping an eye out for other symptoms such as severe headaches, stiff neck, spots on the body, low blood pressure, shortness of breath, difficulty breathing or rapid breathing.
People with compromised immune systems, such as those with HIV or cancer, should seek medical help as soon as a fever develops. In addition, those who have diabetes, kidney problems or have recently undergone surgery should give greater importance to the symptom.
In these cases, it is essential to carry out a check-up to ensure that everything is ok with the body or that other medical interventions are necessary.
Attention with children
When fever strikes children, it is essential to redouble attention, especially if it exceeds the temperature of 37.5°C in babies up to three months, and reaches more than 39°C in young children. It is also important to check for other associated symptoms such as a runny nose, cough or diarrhea.
Often, a fever in children does not indicate something serious. It can arise due to an ear infection, gastroenteritis or viruses. However, it is also a symptom of diseases such as meningitis, kidney infection, and pneumonia.
In addition, there is a risk of febrile seizures when the body temperature rises rapidly. In such cases, there is loss of consciousness, tremors of limbs on both sides of the body, eye rolling, and/or body rigidity. It usually does not cause sequelae, but it can happen again.
Parents should be aware if the child is very irritated, cries a lot, with a “soft” body, apathetic (no reaction), does not want to eat. See a pediatrician immediately if you notice that the skin is red, there is difficulty bending the neck, incessant vomiting, absence of peeing, mental confusion and difficulty breathing.
Ways to reduce fever and recommendations
You’ve probably heard that to lower your fever at home, it’s best to take a cold shower. However, the experts consulted by Live well highlight that the ideal is to keep the water warm, helping to relax and reduce body temperature.
Anyone with a fever should also drink plenty of fluids to prevent dehydration. It is important to drink water, juices and teas. This also helps to regulate body temperature.
Another recommendation is to rest, as any activity raises the temperature. Also avoid excess clothes and blankets so as not to retain heat.
Also, cold compresses with a damp towel on the forehead and torso can help bring down a fever.
Even if the fever reduces your appetite, you still need to eat properly. Invest in a light and nutritious diet, with easily digestible foods such as broths, soups and purees.
Sources: João Pratsinfectious disease specialist at BP – A Beneficência Portuguesa de São Paulo; Igor Brasil Brandãoinfectious disease specialist at Hospital da Bahia and Jaime Emanuel Britoan infectious disease specialist at the Alcides Carneiro University Hospital, in Campina Grande (PB), linked to the Ebserh network.
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