6 Reasons You're Spotting After Exercise When You're Not About to Get Your Period

Vaginal bleeding after a workout can be alarming. And if it happens more than once or twice, it could be a sign of an underlying problem that needs to be addressed.

"Spotting after exercise isn't that common, and it usually does indicate that something is a little abnormal with a woman's hormones or anatomically," says Jennifer Wu, MD, an ob-gyn at Lenox Hill Hospital in New York.

Here, Dr. Wu shares some of the most likely reasons why exercise can cause spotting and what you can do about it, plus other possible culprits behind bloody discharge after exercise that may not necessarily be tied to your workout.

Uterine polyps are small, noncancerous growths that can cause heavy or irregular periods and spotting in between periods. They typically stay within the uterus but sometimes they can extend into the opening of the cervix or the vagina.

Spotting from a polyp can happen anytime, but it may be more likely after exercise or sex because polyps can bleed from irritation or contact, Dr. Wu explains.

Risk factors for uterine polyps include being perimenopausal or postmenopausal, having obesity, taking tamoxifen (a medication for breast cancer) and taking hormone therapy to help manage symptoms of menopause, according to the Mayo Clinic.

Small polyps may clear up on their own over time. But in some cases, your gynecologist might recommend hormonal medications to reduce bleeding from a polyp or outpatient surgery to have the polyp removed, according to the Mayo Clinic.

While specific numbers vary, reaching a very low body fat percentage can cause your period to become irregular, which could lead to spotting during exercise or at other times. (In some cases, low body fat can also make your period stop altogether. Doctors call this exercise-induced amenorrhea.)

"This typically applies to extreme athletes with a lot of muscle mass," Dr. Wu says. "It's more common during training season, and then periods may become more normalized during the off season."

In some cases, exercise-induced period loss can also happen from not eating enough.

See your doctor if you're concerned that your body fat levels have affected your period. Amenorrhea can increase the risk for osteoporosis and may mean you're not getting enough energy to adequately fuel your exercise, according to the Cleveland Clinic.

Sometimes what appears to be spotting could actually be caused by chafing while you're working out. This might be the case if you see bright red spotting after exercise — that color is more likely to be caused by an injury (as opposed to dark red or brown spotting, which is more likely to come from inside your body).

"Irritating clothing could cause bleeding externally or at the entry of the vagina," Dr. Wu says.

Try changing up your workout clothes. Stretchy, form-fitting bottoms work well for higher-intensity activities like running or biking; looser ones can be good for walking, gentle yoga or strength training. Pay attention to material, too: Moisture-wicking fabrics like polyester or polypropylene are a better choice than slow-drying ones like cotton, per the National Library of Medicine.

And consider incorporating anti-chafing products into your routine.

Birth control pills or IUDs, hormone therapy, miscarriage and other pregnancy complications and polycystic ovary syndrome all cause changes in hormones that could, in some instances, trigger vaginal bleeding at any time, including after exercise, according to the Cleveland Clinic.

Talk to your doctor about your spotting plus any other symptoms you might be experiencing, your reproductive health history and your current birth control use. There might be another type of birth control or hormone therapy that could result in less bleeding for you, and they might suggest testing to rule out pregnancy or other underlying health conditions.

Urinary tract and sexually transmitted infections can sometimes cause spotting or blood in your urine that you might notice after exercise or at other times, per the Cleveland Clinic.

You'll likely need antibiotics if an infection is the cause of your bleeding. Talk to your doctor about your symptoms. They'll likely do a blood and/or urine test to determine what's really going on.

Spotting can have a number of other causes. But they're not typically linked to exercise specifically, so breakthrough bleeding can happen at any time, Dr. Wu points out.

According to the Cleveland Clinic, these can include:

• Medical conditions, like bleeding disorders, thyroid problems, adenomyosis, uterine fibroids, cervicitis or endometrial hyperplasia
• Cervical or endometrial biopsies

There may not be a simple or quick solution to some of these underlying health concerns. If you and your doctor think you could have something more serious going on, you'll likely need to go through some testing to figure out what's causing your spotting. Then, together, you'll decide on the best course of treatment.

Spotting just once or only during a single month — whether while exercising or not — likely isn't anything to worry about. But between-period bleeding that happens more often isn't normal and could be a sign of an underlying problem.

"If it's been happening for more than two or three months, I'd see the doctor and get a workup," Dr. Wu says. You should also always see a doctor if your spotting after exercise is accompanied with new or worsening pain.