When it comes to periods, “normal” encompasses a lot of things. That's because different people have different flows, different cycle lengths, and different levels of cramps. But what about period length? We talked to Kristyn Brandi, MD, an OB/GYN and family planning specialist at Rutgers University, New Jersey Medical School in Newark, NJ, about what long periods could indicate.
According to the Mayo Clinic, normal menstrual flow can last anywhere from two to seven days, and irregular periods — in which the length of your period varies from month to month — are common, especially for people just beginning to menstruate and for people who are close to menopause. “Everyone's period is different, and there are some women who have long periods every period,” Dr. Brandi points out.
“Things to note are if your periods change from being lighter to heavier,” Dr. Brandi says. “There is often a cause of this, like fibroids, that your doctor can help you manage.” Other conditions that may cause overlong periods include uterine polyps, adenomyosis, uterine or cervical cancer, inherited bleeding disorders such as von Willebrand's disease, and liver or kidney disease. Taking certain kinds of medication, including anti-inflammatory medications and anticoagulants, can also lead to long periods.
Overlong periods can also be “a sign of a miscarriage where the pregnancy was never diagnosed,” Dr. Brandi says. This isn't unusual; according to the Mayo Clinic, between 10 and 20% of known pregnancies end in miscarriage, but "the actual number is likely higher because many miscarriages occur so early in pregnancy that a woman doesn't realize she's pregnant." Your first period after a medical abortion may also be longer than usual.
If you recently started or changed birth control, that could also be a factor. Longer and heavier periods are a common side effect of copper IUDs, particularly in the first few months after insertion, as well as birth control shots and implants (again, during the first few months after you begin use). Your first period after taking a morning after pill may also be longer than normal.
In general, it’s best to check in with a professional. Dr. Brandi advises, “If your period lasts longer than a week, or you are having a heavy period with symptoms of being anemic (low blood count, like dizziness, shortness of breath, chest pain), you should see your OB/GYN.”