19.07.2021 – 19:21
Most medical experts define a low-grade fever as a body temperature between 37.2 and 37.9 degrees Celsius. Others use a less narrow definition, referring to a low-grade fever as a body temperature ranging from 37.7 to 38.8 degrees Celsius.
The body normally maintains a temperature of about 37 degrees Celsius. Research shows that even in healthy people, normal body temperatures can vary by up to 1.5 degrees.
Normal body temperature can fluctuate based on several factors. Some of those factors include how you measure your temperature (for example, orally or in your armpits), what time of day it is measured (temperature tends to be higher in the evening than in the morning) and whether you are menstruating.
Aside from a raised body temperature, some people with low-grade fever will not have any noticeable symptoms. Others may experience:
- Muscle aches
- Loss of appetite
- Low urine output
A fever, even if it is mild, is a sign that something is wrong with your body. A fever indicates that the immune system is creating a defense against an alien invader, be it a virus, bacteria or other matter.
Experts are not exactly sure why the body responds to infections and diseases with an elevated body temperature, but they think some disease-causing microbes are less likely to thrive at higher temperatures. They also theorize that elevated body temperatures may better allow certain immune cells to seek out and destroy anything that is attacking the body.
What are the common causes of low-grade fever?
Both viral and bacterial infections can cause low-grade fever. Some common culprits include:
Rhinoviruses (common cold)
Viral gastroenteritis (otherwise known as stomach flu). Examples of these include rotavirus, common in infants, and norovirus, which generally affects adults and is highly contagious.
Chickenpox (varicella-zoster virus)
Rubella (also called German measles)
Urinary tract infections
Cellulite, an infection of the skin and surrounding tissues
Escherichia coli (E. coli): While some types of E.coli, a bacterium that lives in the gut, are harmless, others can produce serious illness.
Infectious mononucleosis (mono): This is a highly contagious disease, commonly affecting adolescents and adults, often caused by Epstein-Barr virus infection.
Some autoimmune diseases, such as rheumatoid arthritis and lupus, may exhibit a low-grade fever. In fact, up to 86% of people with lupus experience fever, usually of a low degree.
Some malignant tumors (cancers) can cause cellular changes in the body that produce fever. Moreover, the chemotherapy used to treat some cancers can destroy the white blood cells that fight disease in the body, making you more susceptible to the infections and fevers that come with them.
The general rule is to treat a low-grade fever only if it causes you discomfort. And some experts say that does not happen until a temperature reaches 38.8 degrees Celsius and above.
There is also a theory that says that when you suppress a fever, you also suppress the production of disease white blood cells by striking the disease, prolonging the disease.
When you want to treat a low-grade fever, acetaminophen (Tylenol) and ibuprofen (Advil) are good choices (read the package instructions for proper dosing or ask your doctor).
Aspirin is another option, but never give aspirin to children or teens unless instructed to do so by your doctor. Aspirin use in this age group has been associated with a serious and potentially deadly disorder called Reye’s syndrome.