Periods can suck, but they can also be comforting, in a way. For many women, that monthly spate of cramping and bleeding is a sign that everything inside the body is operating exactly as it should be.
That’s why even one irregular cycle — what gynecologists call “abnormal uterine bleeding” — can be so worrisome.
Pregnancy is the most common cause of irregularity, according Dr. Mary Rosser, director of the division of general obstetrics and gynecology at Montefiore Health System. But she told INSIDER that it’s not the only thing that can throw your cycle out of whack.
Here’s a breakdown of nine possible reasons for abnormal bleeding — and what you should do if you notice that something’s off.
First, you have to know what counts as irregular.
“Typically, abnormal bleeding falls into broad categories,” Rosser said. “You can have regular [periods] that are either heavy or longer, you can have bleeding between your periods, and you can just have irregular bleeding that’s due to ovulation problems, [or] no bleeding at all.”
Rosser said doctors define periods as either “normal” or “abnormal” based on three criteria: how regular your cycles are, how long the bleeding lasts, and how much you’re bleeding.
A normal cycle can be anywhere from 24 to 38 days, as long as it’s consistent, Rosser said. Normal bleeding lasts five to seven days — if it’s eight to 10 days or more, that’s considered prolonged bleeding. A normal cycle also requires you to change your pad or tampon three or four times a day. If you’re changing every hour for the whole day, then your bleeding is abnormally heavy.
If you’re not already using a period-tracking app, you might want to start. It’s an easy way to figure out what’s normal for you.
1. You’re really stressed out.
“There are factors that affect our brain [which] affect our ovaries which in turn affect our menstrual cycle,” Rosser said. “Stress is one of them.”
Broadly speaking, stress can suppress the hormones that regulate ovulation, or the release of an egg from one of the ovaries. If ovulation doesn’t happen, a period won’t happen either.
2. You started exercising really hard.
“Someone who starts increasing their exercise may miss their periods,” Rosser said. Just as with stress, it can impede ovulation. If there’s no egg in the uterus, the uterus won’t build up its usually monthly lining, and there will be nothing for it to shed.