Fever, also pyrexia, is a condition of elevated body temperature that most often occurs as a concomitant of defense against invading living microorganisms or other substances recognized as foreign, and more rarely occurs in the context of otherwise caused inflammatory processes, trauma, or as a concomitant of some tumors. Fever should be distinguished from elevated temperature.
What is fever?
A fever is an increase in body temperature. A fever is said to occur in humans when they exceed their normal temperature, which is between 36°C and 37.9°C. A fever is an increase in body temperature. A human being is said to have a fever when his or her normal temperature is exceeded, which is between 36°C and 37.9°C. From 38°C one speaks of light fever, the condition becomes dangerous, if the temperature exceeds 40°C. Fever does not only manifest itself in this way – the patient feels more fatigued and sick at the same time, the higher his body temperature rises. He often also sweats and may suffer from other accompanying symptoms. The processes associated with this are based on complex physiological reactions, which include a regulated and limited increase in body temperature actively induced by the organism. The latter arises as a result of a temperature setpoint change in the hypothalamic thermoregulatory center. Fever is thus an example of a regulated change in homeostasis. Contrary to a common misunderstanding, fever is thus in most cases not the cause of disease, but part of the organism’s response to disease. Accordingly, although it is a common practice to symptomatically reduce fever above a certain level in order to prevent supposed harm to the patient, this common practice often does not correspond to the state of research in fever physiology. Instead of routinely lowering fever above a certain temperature, symptomatic therapy should be based on the patient’s condition and secondary risks of fever for specific patient populations.
Causes
Fever is an immune response of the body of organisms of the same temperature, which includes all mammals and thus also humans. It is their reaction to the invasion of living foreign bodies and in this way they try to kill them. The principle of operation is simple: fever attacks enzymes belonging to the group of proteins. These are necessary for metabolic processes and many other important processes in the body of all living things. However, they can only survive at certain temperatures, otherwise they are irreversibly destroyed – this temperature optimum is different for every living being. The so-called denaturation of enzymes can be seen, for example, in a fried egg: when it is heated, the proteins turn white and do not return to their original state. If this happens in the living organism, it dies – this is how the body kills bacteria, among other things. In the case of injuries or open wounds, the body often increases the temperature in the corresponding area as a preventive measure. This is to prevent invading bacteria from finding a comfortable habitat there. The body can also react with fever in the case of bruises or other injuries. Some tumors also trigger fever in the body. In these cases, the fever results from complex concatenations of reactions and does not always occur. It is usually accompanied by other symptoms that have also resulted from the neoplasm.
Diseases with this symptom
- Common cold
- Meningitis
- Three-day fever
- Angina tonsillaris
- Flu
- Pneumonia
- Measles
- Scarlet fever
- Gastrointestinal flu
- Bacterial infection
- Tuberculosis
- Non-Hodgkin’s lymphoma
- Otitis media
- Appendicitis
- Thyroiditis
- Bechterew’s disease
- Systemic lupus erythematosus
- Blood poisoning
Diagnosis and course
If there is a suspicion of fever, that can be diagnosed either by a doctor or the affected person or a relative / acquaintance by measuring the body temperature. This is done with the help of a clinical thermometer, which is usually placed under the armpits or in the anus. Doctors speak of an elevated temperature as early as 37.6°C.In addition, the doctor will ask about accompanying symptoms – in the case of a flu-like infection, for example, there is a cough or headache and pain in the limbs. Blood and stool tests to determine the inflammation values round off the diagnosis. Since different types of fever exist, it is not possible to speak of the course. However, it is noticeable in the respective curves that those show ascents and descents. The former are often rapid, while the descent is slower. Peak values can be observed at certain, always the same times (for example, always at noon or in the evening).
Diseases
- Common cold
- Bronchitis
- Angina tonsillaris
- Flu
- Scarlet fever
- Measles
- Rubella
- Chickenpox
- Typhoid fever
- Syphilis
- Gastrointestinal flu
- Pfeiffer’s glandular fever
- Yellow fever
- Spotted fever
When should you go to the doctor?
Fever is considered by many people as a clear sign of illness. Others wonder to what extent fever is actually cause to see a doctor. Body temperature readings between 38 °C and 39 °C are considered a moderate fever, and readings above that are considered a high fever. Anyone who feels reasonably well despite a moderate fever and is not suffering from a chronic illness can often manage with home remedies and does not need a doctor. At a body temperature of 39 °C and above, a visit to the doctor is advisable. Chronically ill people, pregnant women, infants and small children should consult a doctor at the latest when they have a high fever. Fever should not be considered exclusively as a symptom of a cold or other infection. Fever can be one among many symptoms of a possibly even life-threatening disease such as cancer. For globetrotters, a fever occurring after returning from a trip should always be considered a tropical disease such as malaria. Rheumatism and other autoimmune diseases also frequently cause fever. Treatment of the fever by a doctor is wiser than enduring the fever alone, especially when the fever is high. To this end, an experienced doctor knows when a fever under his control contributes to the healing process and when it is better to prescribe fever-reducing drugs. In addition, fever gradually weakens the body more and more, and a visit to the doctor in addition to the fever is exhausting.
Treatment and therapy
Regardless of the cause, fever is first treated with antipyretic agents to reduce fever. Well-known agents include acetaminophen or ibuprofen. If the cause of the fever can be treated medically, it is an undesirable, unnecessary reaction that only puts the person in danger. If his body temperature rises higher than 40°C, his own enzymes denature and he kills himself with the fever. If fever occurs as a reaction to the invasion of bacteria, it is treated with antibiotics. These are administered in the form of tablets, for example, or applied to wounds as an ointment. Viruses can also trigger fever, for example in the case of influenza. In this case, a neuraminidase inhibitor is administered to prevent the viruses from spreading further. In fever, the need for fluids is increased, so special attention must be paid to adequate fluid intake in this case. In the first phase, during which chills are often experienced, heat loss from the body should be avoided. Cooling measures are useful at extremely high temperatures, then ice bags are placed in the groin, for example. Physical rest, i.e. avoidance of physical and mental overexertion, is recommended. Fever above 40 °C must be treated by antipyretic therapy. Children and the elderly in particular are sensitive to high fevers. In young children, febrile convulsions may occur, especially after a rapid rise in fever.
Outlook and prognosis
When a patient has a fever, he or she usually does not need to be hospitalized and only rarely needs to see a doctor. Fever is triggered whenever the body fights off a virus or infection and is usually the precursor to a cold and flu. Anyone suffering from a fever should, above all, give the body plenty of rest and relaxation. Rest will allow the immune system to regenerate. In most cases, the fever drops in patients after a few hours or after a few days at the most.With fever, the affected person should in no case go to work and also avoid other physical activities, because this puts a lot of strain on the body, which slows down the healing process. If the fever is relatively high, medication can also be taken to alleviate the fever. These include, above all, painkillers, which can also reduce the fever. In case of a very high and long-lasting fever, a doctor must be consulted in any case. In this case, the fever could be associated with a worse infection. In most cases, however, fever is quite harmless and can be treated relatively well by home remedies and bed rest. A week should be allowed for complete recovery.
Prevention
Fever due to infection is the only form that can be effectively prevented. For example, you can protect yourself from colds by wearing warm clothes, and you can get vaccinated against influenza. If you do fall ill, it is important to take it easy – and you should also see a doctor to have the illness treated in time. In the case of open wounds, hygiene is the top priority to prevent fever. The wound must be cleaned, disinfected and kept germ-free according to the doctor’s instructions. Preventive fever of the body can be treated with antipyretics, but should seek the advice of the doctor.
This is what you can do yourself
Fever usually occurs whenever the body has to defend itself against a virus or other invader in the body and has to raise the body temperature to do so. Therefore, a fever is always a sign of infection, flu, or just a cold. Most of the time, the fever goes away on its own without the patient having to do anything about it. It is important to give the body rest and opportunity to recover. Bed rest speeds up the healing process. If the fever is high, the patient can also help it along with medication. Here, fever-reducing medications can be effective. However, they should only be taken in a small amount, as they are relatively difficult for the stomach to digest. A doctor only needs to be consulted if the fever is extremely high and does not disappear on its own. It is important that in case of an infection the patient takes plenty of water. In the case of an infection caused by certain foods, only water and lean food should be consumed here to protect the stomach. In order to always keep an eye on the fever, the use of a clinical thermometer is highly advisable. This is available in any pharmacy and gives relatively reliable values about your own body temperature.