The taboo around periods and menstruation is still, sadly, a thing. Consider this: When was the last time you, a person with a uterus, loudly announced to your coworkers that you needed a tampon, thanked the person who gave you one, and then wagged it around in your hand en route to the bathroom? Chances are, you discreetly asked your work bestie for one and then rapidly shoved the package into your pocket. Once said menstrual product was in place, you probably tried to forget it—and the fact that you’re having your period—entirely.

But as Allison K. Rodgers, MD, an ob-gyn and endocrinologist with the Fertility Centers of Illinois, tells SELF, if you’re not thinking about your flow, you’re doing your health a huge disservice. “A period is like a fifth vital sign,” she explains. “If someone isn’t getting a period, or it’s irregular or painful or heavy, it makes me wonder what’s wrong.”

Plus, as Dr. Rodgers points out, a lot of people don’t even realize they’re overlooking menstruation. “People are overextended with their jobs, families, and obligations. So many of my patients just don’t find it important enough to remember or just don’t realize the importance of a period.”

Here are six major health issues an absent, irregular, or extremely heavy or painful period can reveal (aside from the obvious).

1. You’re super stressed.

While nobody’s cycle looks exactly the same, a generally healthy person will bleed for two to seven days every 21 to 35 days. According to Dr. Rodgers, your period is like the final act of a symphony, one driven by “an orchestra of hormones released from the ovaries and pituitary glands.” Those hormones make your uterine walls thicker so it’s easier for an egg to implant itself and lead to a pregnancy. (We’ll call that the crescendo in this musical analogy.) When there’s no sperm to fertilize the egg, the uterine lining sheds, and voilà! There will be blood!

But, as Dr. Rodgers says, “If there’s something wrong, our body shuts off reproduction because it doesn’t feel like it’s healthy enough to support a pregnancy.”

“Reproduction in the animal world happens when the animal is safe and protected,” Lubna Pal, MD, a professor of obstetrics and gynecology at Yale, tells SELF. “What happens when you stress an animal? Their reproduction shuts down.” She notes that humans are no exception here—when you’re tense, you might feel the effects of that menstrually: Some research on people with uteruses in high-stress jobs found it can result in shorter (and sometimes longer), or completely absent, bleeding. Plus, as SELF has previously reported, stress can also cause sleep issues, bowel problems, hair loss, and an increased risk of heart disease, hypertension, type 2 diabetes, arthritis, and anxiety disorders.

2. You’re exercising too hard.

While anxiety and depression can absolutely stress you (and, by association, your ovaries) out, Dr. Rodgers notes that physical tension can have the same effect, particularly if you have rapidly lost weight or aren’t taking in enough calories. “If you are in a starvation state, you’re trying to survive,” Dr. Rodgers says. “In an extreme weight loss situation, your body isn’t going to expend energy that it doesn’t have to to keep you alive. It knows you’re not healthy enough to carry a baby, so your reproductive system shuts off.”