Written on December 19, 2023 by Amy Harris, MPH, RN. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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Medical providers and women’s health specialists want the menstrual cycle to be considered the fifth vital sign because it is such a sensitive indicator of your overall health and well-being.
There are many different causes for changes in your period—sexually transmitted diseases (STDs) are just one possible cause of menstrual disruptions. Everlywell can help you cross STDs off your list of possible causes of your menstrual changes—we offer at-home testing and online STD consultations to put your mind at ease.
Of the 20 million new sexually transmitted infections (STIs) that are reported each year in the U.S. by the Centers for Disease Control (CDC), some of the STIs that may cause menstrual changes are [2,3]:
Bacterial vaginosis is not technically considered a sexually transmitted infection, but it can increase your risk of getting other STDs that may affect your period.
If untreated, certain STDs can progress to life-threatening infections that affect the health of all of your body systems and ultimately lead to death. At these later stages, HIV/AIDS, hepatitis B and C, syphilis, and cancers caused by HPV could also cause changes in your menstrual cycle, including stopping periods altogether (called amenorrhea).
The most common changes STDs might cause in your period are [5,6]:
Most STDs won’t affect your periods unless they progress to become a more severe infection, called pelvic inflammatory disease (PID). People assigned female at birth (AFAB) develop PID when certain bacteria, such as those which cause chlamydia or gonorrhea, move up from the vagina or cervix into the reproductive organs. PID can impact your uterus, fallopian tubes, and ovaries.[7,8]
If not treated, PID can be life-threatening and lead to chronic pain (pain that does not go away) in your pelvis, ectopic pregnancy (a pregnancy outside of your uterus), and infertility.
Any time you have pelvic pain or pain with sex and changes in your period, it is a good idea to see a healthcare provider for treatment.[5,6]
Yes, if you are having sex without a condom during that time of the month, you might be putting yourself at risk for an STD. So why do people choose to have sex during their period? Because period sex can help with cramps, mood, and fatigue through the release of feel-good hormones.
Keep in mind, however, that if you have sex without a condom during your period, you might be at greater risk of transmitting or contracting one of the STIs transmitted by viruses through your blood, such as :
Research has shown that people reporting having sex during their menses were more likely to report having a history of HIV, chlamydia, genital herpes, genital warts (condyloma), gonorrhea, syphilis, trichomonas, hepatitis B, chancroid, or bacterial vaginosis. Scientists believe changes during your menstrual cycle may make it harder for your immune system to fight infections.
What you may be surprised to learn is that many of the most common STDs don’t have any symptoms at all.  Chlamydia and gonorrhea, especially in people assigned male at birth (AMAB), may not cause noticeable symptoms. Other STD symptoms can be subtle and easy to brush off as something else. You may be confused about whether an STI, a yeast infection, or a urinary tract infection is the cause of your symptoms.
STD symptoms vary, depending on where the infection might be (mouth and throat, vagina, penis, or anus). STDs will have different symptoms depending on whether you have male or female body parts.
If you are AFAB, keep an eye out for other common STI symptoms besides menstrual changes, such as [3,6]:
Because the menstrual cycle is such a sensitive indicator of health and well-being, many different factors and health conditions can disrupt it. Besides an STD or PID, some of the other reasons why you may have changes in your period are :
At first, this long list of possible diagnoses can seem overwhelming. You can start shortening the list by crossing off some of the more accessible tests or evaluations first—such as taking a pregnancy test or an at-home STD test. Keeping track of your menstrual cycles and any other symptoms on your phone or a calendar can also help you begin to see a pattern in your menstrual changes.
If you have irregular bleeding or other changes in your menstrual cycle, other suspicious STD symptoms, or you or your partner have had a different partner, it is always a good idea to test for STDs.
You might want to consider contacting a healthcare provider if you have painful or irregular periods or any of the following symptoms :
Remember that not everyone has a regular cycle. It is okay to have an irregular cycle. Menstrual cycle length and the amount of flow you have can also change over your lifetime.
According to the CDC, the incidence of STIs is at an all-time high. There are 20 million new STI cases in the United States each year. Half of those new cases are in sexually active people between the ages of 15-24.
During this age range, people can also have changes in their menstrual cycles. While many STIs don’t cause any symptoms, some can cause irregular bleeding or other changes in your cycle.
If you are worried about changes in your period or whether or not you might have an STD, Everlywell can help put your mind at ease. We offer confidential, at-home STD testing and same-day telehealth STD consults so that you can find answers to all of your questions about how STDs affect your period.
Amy Harris, MPH, RN has a master's degree in Maternal and Child Health from Harvard T. Chan School of Public Health. She attended Yale School of Nursing and Boston University School of Public Health to become a certified nurse midwife (CNM). She has worked for over 20 years in clinical and public health practice. She specializes in women's reproductive health care, healthy literacy, and writing about health and wellness.