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Fever is a term used for elevated body temperature. The medical term used for it is called pyrexia. For a healthy adult, the normal body temperature is 98.6° Fahrenheit or 37° Celsius. A low-grade fever is not considered a cause of concern because it eventually goes away on its own. But temperature above 102° F can indicate an underlying infection or disease. For newborn babies or infants, even a slightly elevated temperature should be considered. 


Fever is a symptom of many diseases. It occurs as an immune response to fight off an illness or infection. In most cases, it can be due to a viral, bacterial, or parasitic infection. Common infections that present with fever include influenza, common cold, strep throat, malaria, gastroenteritis, etc. Certain inflammatory conditions can also raise your body temperature, such as rheumatoid arthritis, sinusitis, etc.

Fever can also occur if you have gotten a major tissue injury which can happen in case of an accident or trauma. Certain medications can cause fever as a side effect. In some cases, a medicine may elicit an immune response from your system because you are allergic to one of its ingredients.

Unexplained fever is considered a cause of concern and needs to be evaluated. Besides medical conditions, fever can also occur due to hormonal fluctuations and physiological changes. If you are going through a period of stress or anxiety, you may develop a mild fever in such cases. Some females also experience fever episodes during menstruation. A fever where no cause can be identified is also known as a fever of unknown origin (FUO). 

Risk Factors And Epidemiology

Fever can occur at any age of your life. However, people with weakened immunity are more at risk of developing a high-grade fever. This is common among infants and young children. Because their immune systems are still developing, exposure to environmental pathogens can trigger their immune system to cause fever. Those with immunocompromising diseases such as HIV, lupus, etc., should be concerned if they develop a fever. Similarly, people on immunosuppressant medications or those undergoing chemotherapy/radiotherapy should also note changes in their body temperature. 

Signs And Symptoms

Fever itself is a sign of many diseases or illnesses. You may also experience chills or shivers when you have a fever in many cases. This way, your body’s core temperature is raised to defend against harmful pathogens. Depending on the condition, fever may present with other symptoms such as sweating, weakness, dizziness, headache, tiredness, coughing, sneezing, runny nose, pain in one or more parts of the body, etc. Special care is needed among children. If a child develops fever and shows other signs of physical or mental deterioration, seek immediate medical help to reduce the risk of any severe complications. 


A fever can be diagnosed by measuring your core body temperature. This can be done in multiple ways using mercury or digital thermometers. If you have a high-grade fever over 102 or 103° F, you will have to consult a medical expert immediately. Notice the pattern of fever onset and duration because it is significant in diagnosing certain illnesses. Your doctor will also inquire about other associated symptoms to suspect a possible cause. Physical examination is done in some cases. If a disease or infection is suspected, lab tests such as CBC, ESR, urinalysis, culture test, etc., will be required to confirm the diagnosis. 


If you have a low-grade fever (below 101° F), your doctor may not recommend any medicine or treatment. The reason is that it can be a sign of an active immune response to an infection or disease. Suppressing fever, in this case, can be more harmful than beneficial. However, high-grade fever needs to be checked for its possible causes. Rest well, drink plenty of fluids and avoid strenuous activities. Wear light clothing and try to stay in an area where room temperature is not too low or high. Wet cloth or pads are used to lower body temperature to some extent. This is more helpful in the case of children where medicines should be avoided unless necessary. If a child develops high-grade fever and other symptoms, take them to medical care as soon as possible. 


Antipyretic medications such as acetaminophen, ibuprofen, aspirin, etc., are commonly available to treat fever. These medications should not be taken in every case of fever. As mentioned above, fever is a normal immune response. Suppressing it may cause more problems in some cases. Ask your doctor or pharmacist before taking any drug. If you have an infection, your doctor may prescribe antivirals or antibiotics to eliminate the offending pathogen. 


The majority of fever cases recover well in a few hours or days. Resting, fluid intake, and thermoregulation can set your body temperature back to normal. Medicines should only be taken when necessary and recommended by your healthcare provider. Persistent fever for more than three days can be a dangerous sign and lead to complications if not treated on time. 


Fever is a natural immune response so it can only be prevented by lowering your exposure to harmful pathogens or environmental hazards. Wash your hands regularly with a soap or handwash. Children should be taught the correct way to wash their hands. Take special care if you work in a medical care facility or as a caretaker. Keep a sanitizer with you when going outside. If you are coughing or sneezing, cover your mouth with your elbow rather than your hands to limit the spread of that particular infection.

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 18, 2023.



Fever - Better Health Channel

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