Internal fever does not actually exist, being just a popular way of expressing the feeling that the person has that the body is very hot, despite the thermometer not showing an increase in temperature.
In these cases, the person may present the same symptoms as in the case of a real fever, such as malaise, chills, headache, tiredness and cold sweat, but the thermometer remains at 36 to 37ºC, which is a temperature considered normal and not indicative of fever.
See how to use the thermometer correctly.
Internal fever symptoms
Typically, “internal fever” appears associated with symptoms such as:
- Feeling of heat;
- Cold sweat;
- Discomfort;
- Headache;
- Tiredness;
- Lack of energy;
- Chills.
However, despite all these symptoms being present, there is no increase in body temperature.
It is important that the person pays attention to the duration of signs and symptoms and the appearance of others, as it may be necessary to go to the doctor so that tests can be carried out to identify the cause of the fever and, thus, treatment can be started.
Main causes
The main causes of internal fever are:
1. Stress and anxiety
Stress and anxiety can cause a feeling of internal fever, with chills often described as shivers running down the spine. This is considered a response to a psychological event and disappears when the emotion subsides.
2. Ovulation
Ovulation is accompanied by increases in progesterone levels, which leads to an increase in body temperature, resulting in the feeling of internal fever and chills.
3. Physical activity
Practicing intense physical activity can also cause a feeling of internal fever, as the body temperature increases as the exercise is performed. Thus, as a consequence of the increase in body temperature, sweat and chills are produced, in some cases.
4. Infection
In infection by viruses or bacteria, the immune system is activated, promoting several defense mechanisms to systematically attack the invaders. One of these mechanisms is chills, which increase the body temperature, leading to the feeling of internal fever.
5. After meal
Some people may experience “postprandial syndrome” after a meal due to the increase in sympathetic nerve activity after a meal, which leads to chills, cold sweat, anxiety, palpitations and a feeling of internal fever.
6. Cold environment
When exposed to cold, it is common for a person to shiver in an attempt to increase their body temperature, which can result in a feeling of internal fever.
7. Hypothyroidism
Hypothyroidism is a condition in which there is a change in the functioning of the thyroid, with a decrease in metabolism, which can cause a feeling of internal fever.
8. Hypoglycemia
Hypoglycemia, which is characterized by a decrease in blood sugar levels, can promote the release of epinephrine and norepinephrine in the cells’ attempt to gain energy, which can cause tremors, chills, cold sweat and mental confusion, as well as a feeling of fever. internal.
9. Low weight
People with very low weight have a small amount of fat tissue, which can favor changes in body temperature.
Can internal fever be COVID-19?
Internal fever can happen when the body tries to fight an infection, appearing as a first sign before the fever. Therefore, it is possible that some people infected with COVID-19 may experience an internal fever before any other symptoms.
It is essential to observe other symptoms that may arise and that are more indicative of infection with the new coronavirus, such as dry cough, excessive tiredness, loss of taste and smell or fever. Find out what the main symptoms of coronavirus are.
In case of suspected infection with the new coronavirus, it is important to contact “Disque Saúde” at number 136, where you will receive all the guidelines to be followed.
What to do if you have an internal fever
When a person thinks they have an internal fever, they should take a warm bath and lie down to rest. The cause of this feeling of fever is often stress and anxiety attacks, which can also cause tremors throughout the body.
It is only recommended to take medication to reduce fever, such as Paracetamol or Ibuprofen, if advised by your doctor and when the thermometer registers at least 37.8ºC. As in the case of internal fever, the thermometer does not show this temperature, you should not take any medicine to try to combat a fever that does not exist. Therefore, if necessary, you should simply remove excess clothing and take a bath with warm water, to try to lower your body temperature and alleviate discomfort. Discover some home remedies for fever.
If symptoms persist, you should go to the doctor for a physical examination to find out what could be happening. In addition to blood and urine tests, the doctor may also request a chest X-ray, for example, to check if there is any lung change that could be causing this feeling of fever and discomfort.
It is advisable to seek medical help when, in addition to the feeling of internal fever, the person presents other symptoms such as:
- Persistent cough;
- Vomiting, diarrhea;
- Mouth sores;
- Rapid rise in temperature to above 38ºC;
- Fainting or decreased attention;
- Bleeding from the nose, anus or vagina, with no apparent explanation.
In this case, it is still important to tell the doctor all the symptoms you are experiencing, when they appeared, if anything has changed in your diet or if you have been to another country, for example. If there is pain, it is also advisable to explain which part of the body is affected, when it started and whether the intensity has been constant.
What is fever
Fever is a natural response from the body that indicates that the body is fighting infectious agents, such as viruses, fungi, bacteria or parasites. Therefore, fever is not a disease, it is just a symptom that appears associated with many types of diseases and infections. See when and how to know if it’s a fever.
To find out if it is a fever, enter your temperature into the calculator below:
A fever is only really harmful when it rises above 39ºC, which can happen quickly, especially in babies and children, and cause convulsions. Fever drops to 38ºC, it is considered an increase in temperature or simply a feverish state, not being very serious, only indicating that it is necessary to stay alert and remove excess clothing to try to cool the body to the normal temperature of 36ºC or take a medicine to reduce fever, as well as other natural methods to normalize body temperature.
