Why Does Your Period Blood Smell Metallic or Fishy Sometimes?

When you change your tampon or go to the bathroom on your period, you kind of get up-close and personal with your period blood, which can change from cycle to cycle. But maybe this time you notice something a little off-putting: the smell.

"Menstrual blood contains blood and sloughing uterine lining tissue, thus it may smell differently than blood from a cut, for example," Alyssa Dweck, MS, MD, FACOG, a board-certified gynecologist in Westchester County, New York and INTIMINA's Sexual and Reproductive Health expert told POPSUGAR. But what about when your period blood smells like metal? Or when your period blood smells like fish? Does it mean anything for your health?

Ahead, doctors weigh in on what causes period blood smell, whether any of it is cause for concern, and when you should seek help from your healthcare provider.

Some people who menstruate, in particular, describe their period blood as having a metallic-like scent — according to Dr. Dweck, this is likely because of the iron content in the blood. Dr. Dweck also adds that blood is a bacterial medium and may have a differing smell for that reason too. Remember, though, it's normal for the vagina to have a smell — and no, it's not supposed to smell like perfume or a bouquet of flowers. According to Megan Zaander, MD, a board-certified ob-gyn at Lake Oswega GYN, many people who menstruate will experience a more acidic scent, which has to do with the acidic pH of the vagina. "The vagina is actually more of an acidic environment. So when people kind of pin it down, if it has more of an acidic smell, that's actually normal," Dr. Zaander added.

Some smells are definitely more concerning than others. Dr. Zaander explained she typically tells patients that it's normal for the vulva and the vagina to have a scent, but it's not necessarily normal for these body parts to have an odor. For example, a foul, fishy odor could be a sign of a bacterial vaginosis infection (BV), Dr. Dweck explained. "This is not an STI but rather is caused by an imbalance of the typical bacteria in the vaginal biome. The normal pH in the vagina is acidic. BV can be caused by a disruptor to this pH. Disruptors could include antibiotics, hormone changes, and exposure to multiple sex partners."

According to the Mayo Clinic, abnormal vaginal smells could be the sign of a forgotten tampon, too. Consider that cause for quick action, as wearing tampons for more than eight hours can increase your risk at developing toxic shock syndrome.

Dr. Dweck also added that other infections, such as a yeast infection, can cause a sour type scent, while certain STIs could cause foul-smelling discharge.

You can reduce your chances of period blood smells by keeping up good hygiene (which includes avoiding douching as it can upset your natural pH and cause infection) and changing your pad or tampon regularly.

Ultimately, if the smell of your period blood is concerning you, it's best to schedule a visit with your doctor. They will be able to assess the situation and provide treatment recommendations, if necessary. In the case of bacterial vaginosis, antibiotics are typically prescribed. With yeast infections, over-the-counter remedies may be suggested. And other times, the smell requires no treatment at all. Whatever the cause though, it's nothing to be ashamed about and your doctor will be able to point you in the right direction.