It’s natural for menstrual bleeding to have a slight odor. But if you start noticing anything out of the ordinary, you may want to have a doctor check it out.

Menstruation involves shedding your uterine lining, an unfertilized egg, and blood. It’s completely natural for this combination to have a slight odor after it exits your vagina.

This most likely relates to the vaginal substance itself, but bacteria and acidity can also play a role.

Generally speaking, period odors aren’t noticeable to others. Proper hygiene practices can also reduce period odors and make you feel more comfortable during menstruation.

In some cases, an unusual or unexpected odor may be a symptom of an infection. Noting any other unusual symptoms, such as changes in discharge or pelvic pain, can help determine the underlying cause.

Some people report that their period “smells like death,” though this isn’t necessarily a cause for concern. The strong smell is likely due to blood and tissues exiting their vagina along with bacteria.

The resulting “rotten” smell from bacteria mixed with menstrual flow shouldn’t be strong enough for others to detect. Changing pads and tampons frequently, especially during heavy-flow days, can help.

A “rotten” smell can also occur when you leave a tampon in for too long or forget to remove it.

If you’re concerned that you may have forgotten to remove a tampon, try to feel the opening of your vagina for the strings. If you can’t feel them, make an appointment with a healthcare professional for a vaginal exam to confirm.

Some people report a “fishy” smell during menstruation. Unlike other common odors, fishiness usually indicates a medical condition that a doctor needs to check out.

This odor most often occurs from bacterial vaginosis, a type of infection. You may have bacterial vaginosis if the “fishy” smell also involves:

  • white, gray, green, or yellow discharge
  • a burning sensation, especially during urination
  • itchiness

Bacterial vaginosis may be noticeable during your period but doesn’t result from your menstrual cycle. It results from the overgrowth of vaginal bacteria.

While experts don’t fully understand the exact cause of this overgrowth, bacterial vaginosis seems to be most common in sexually active people. Douching may also increase your chance of developing this type of infection.

Bacterial vaginosis is treatable with antibiotics. Once the bacteria balance out after treatment, you should no longer notice any unusual smells or other symptoms during your period.

Other odor changes during your period can include a “sweaty gym” smell or an odor of onions or salt. Improper hygiene most likely causes these.

Proper hygiene habits can help reduce the usual odors associated with menstruation. One simple habit is to change tampons, liners, or pads every few hours.

Regular showers or baths are also important.

Experts don’t recommend deodorizing products, such as wipes and sprays, because of the possibility of irritation. Try not to douche, as the process can get rid of healthy vaginal bacteria and lead to infection.

Avoid scented tampons and other products, which can cause irritation and allergic reactions. Instead, use unscented products and wear breathable cotton underwear and clothing to keep unpleasant odors at bay.

While some odors are completely natural during your period, others may mean you need to consult with a healthcare professional. This is especially the case if any unusual odors accompany the following symptoms:

  • yellow or green vaginal fluids
  • heavier bleeding than expected
  • abdominal or pelvic pain
  • more severe cramps than usual
  • fever

While most odors are healthy, some may be symptoms of an infection. A healthcare professional can identify or rule out more serious conditions, such as pelvic inflammatory disease.