Why do I keep getting a fever with my period?

Dear Reader, 

Feeling hot and bothered during your period is no fun. For some people who menstruate, fevers are an unwelcome but regular monthly occurrence; however, it seems like your fevers are a relatively new occurrence. There are several reasons why you may be experiencing a fever during your period — pelvic infections, sexually transmitted infections (STIs), stress, or other conditions. Since your fevers are a new development and they seem distressing for you, speaking with a health care provider about your experiences to pinpoint what may be contributing to your “period flu” may be beneficial. 

It may be helpful to first understand what causes a fever and how your period factors into it. A fever is a symptom that can be caused by a variety of illnesses. It most commonly accompanies a viral infection, but it can also have numerous other causes: bacteria, fungus, drugs, toxins, heat exposure, cancer, injuries to the brain, or diseases of the endocrine system. When a virus or other pathogen enters your body, your immune system responds by producing antibodies and other molecules to fight off infection and repair damaged tissues. 

How does your period factor into all this? One of the molecules your body produces to fight off infection is prostaglandin. Prostaglandin is also produced during the menses phase of the menstrual cycle (commonly referred to as your period). Prostaglandin binds to receptors in your hypothalamus, the part of your brain responsible for regulating your body’s temperature, leading to an increase in body temperature (fever) and other symptoms such as uterine cramps. 

You mention that your fever has gotten up to 102 degrees Fahrenheit and that you were unable to go to work. Since these symptoms are a little more severe than a slight spike in temperature, it may be that something else is going on in your body that’s contributing to your fever. Some people who menstruate may develop a pelvic infection during menstruation. A pelvic infection is caused by bacteria traveling into the uterus and causing infection. You mention that you aren’t currently sexually active. If you were in the past, pelvic infections may develop from pelvic inflammatory disease (PID) or STIs. However, STIs are only one cause of these infections. They’re also caused by regular bacteria in the vagina. Common infection symptoms besides lower abdominal pain include fever, unusual discharge that may have a foul odor, painful penetrative sex, painful urination, irregular menstrual bleeding, and pain in the right upper abdomen (rare).

Have you been more stressed than usual lately? It’s widely believed that stress can suppress immune function and increase susceptibility to disease. Researchers have found that during the menstrual cycle, women are more liable to immune system-related diseases during the luteal (21st to 23rd days) phase. Other studies carried out in women have demonstrated that hormonal alterations during different phases of the menstrual cycle affected stress response and immune system function. One caveat of this research is that the identities of those who participated were restricted to those who identified on the gender binary. It didn’t take considerations for those who identify with a different gender but still experience menstruation. 

While stress, infection, or none of the above could be the cause of a fever associated with your period, you may want to speak with a health care provider. They can help you find out more about what’s going on with your body, so you don’t have to take a week off work every month. Good luck cooling your fever!