What Causes Fever?
Under normal circumstances, a person’s body temperature should stay between 36°C and 37°C (96.8°F to 98.6°F). However, in certain situations, the body temperature can rise above this range, which is known as a fever. Specifically, if the temperature reaches 39.6°C (103.3°F) or higher, it is considered a high fever. At this level, the body feels significantly uncomfortable, making it difficult to carry out everyday activities. In such cases, it is advisable to seek medical attention quickly.
Fever is the body’s defense mechanism during illness, helping to enhance the immune system’s activity. The higher the temperature, the more active the immune system becomes, prompting the body to generate heat to fight infections. There are several conditions that can cause high fever, and these can be classified into four main causes:
1. Bacterial and Viral Infections Leading to Fever
A common cause of fever is bacterial or viral infections. The most frequent infection responsible for fever is the cold, caused by over 200 different viruses. Once you become infected with a virus, your body produces antibodies that prevent reinfection by the same virus. However, because there are so many different viruses causing colds, it’s possible to get sick multiple times.
Other viral infections, such as the flu, pneumonia, and tuberculosis, as well as bacterial infections, can also cause fever. In these cases, the body creates a fever to fight off the infection.
Although many people turn to fever-reducing medications, like antipyretics, to lower their temperature, it’s important to be cautious. Fever is part of the body’s immune response, so taking fever medication without medical advice can interfere with the healing process. For mild fever, resting in bed may be sufficient, but if high fever persists, it is essential to consult a healthcare provider.
2. Inflammation and Autoimmune Diseases Triggering Fever
When the body experiences injury or damage, inflammation occurs as a defense mechanism, leading to redness, swelling, pain, and heat. This is another common cause of fever. Examples of conditions that lead to fever due to inflammation include tonsillitis, esophagitis, gastroenteritis, pancreatitis, and otitis media (ear infections). Autoimmune diseases, where the immune system attacks healthy tissues, can also cause high fever. Rheumatoid arthritis is a common autoimmune disease that can lead to fever above 39.6°C (103.3°F).
Interestingly, during a fever, people may feel cold, a sensation called chills. This happens because the brain resets the body’s temperature higher than the usual 36°C to 37°C (96.8°F to 98.6°F). Until the body reaches this higher temperature, it makes the person feel cold.
3. Psychological Factors and Emotional Stress Inducing Fever
In some cases, fever can be triggered by psychological factors. Emotional stress, anxiety, or anger can cause physiological changes, including increased body temperature. The central nervous system responds to emotional stress by stimulating muscle contraction and blood vessel constriction, which can generate heat.
When you feel stressed or anxious, you might notice your face becoming hot, or you might feel as though you’re “heating up.” This is a real physiological response. The most effective way to manage this type of fever is to stop what you’re doing and take a break. A short walk or a nap can help lower your temperature. If these emotional triggers escalate, they may lead to panic or anxiety disorders, which are accompanied by extreme feelings of anxiety, shortness of breath, rapid heartbeat, dizziness, sweating, and shaking. However, these conditions rarely result in a fever higher than 39°C (102.2°F).
4. Other Factors Causing Fever in Adults and Children
There are various other causes of fever, particularly in both children and adults. Certain medications, nutritional supplements, or even foods can sometimes trigger fever. For example, some medications like antibiotics or anti-inflammatory drugs can cause fever as a side effect. If you experience fever after taking a new medication or supplement, it may be worth discussing with a healthcare provider.
During the summer, heatstroke or sunstroke is a common cause of fever, where the body loses the ability to regulate its temperature due to extreme heat. On the other hand, excessive air conditioning can cause symptoms similar to a cold, known as “air conditioning illness.”
If a fever persists, it’s best to seek medical attention. When visiting a doctor, provide specific information about accompanying symptoms such as vomiting, diarrhea, headaches, dizziness, cough, phlegm, or muscle and joint pain.
As previously mentioned, taking fever-reducing medication without consulting a doctor may delay recovery. The most important step when you have a fever is to rest and stay hydrated. If you experience vomiting or diarrhea, drink small amounts of water regularly to avoid dehydration.