A viral fever is any fever that’s caused by an underlying viral illness. Normal body temperature is
98.6°F (37°C). Anything a degree above this is considered a fever.
A variety of viral infections can affect humans, from the common cold to the flu. A low-grade fever is a symptom of
many viral infections. But some viral infections, such as dengue fever, can cause a higher fever.
Read on to learn more about viral fevers, including common symptoms and treatment options.
If you have a viral fever, you might have some of these general symptoms:
• chills
• sweating
• dehydration
• headache
• muscle aches and pains
• a feeling of weakness
• loss of appetite
These symptoms usually only last for a few days at most.
A viral fever is caused by infection with a virus. Viruses are very small infectious agents. They infect and multiply
within the cells of your body. A fever is your body’s way of fighting off a virus. Many viruses are sensitive to shifts in
temperature, so a sudden increase in your body temperature makes you less hospitable to viruses.
How is a viral fever diagnosed?
Both viral and bacterial infections often cause similar symptoms. To diagnose a viral fever, a doctor will likely
start by ruling out a bacterial infection. They can do this by considering your symptoms and medical history, as well
as taking any samples to test for bacteria. If you have a sore throat, for example, they might swab
your throat to test for bacteria that causes strep throat. If the sample comes back negative, you likely have a viral infection.
They can also take a sample of blood or other bodily fluid
to check for certain markers that might indicate a viral
infection, such as your white blood cell count.