period healthYour period can provide key insights into your health. In fact, in late 2015, the American College of Obstetricians and Gynecologists recommended that a period be added as a vital sign for health, similar to blood pressure, temperature, and pulse. Yet even if you have had periods every month for decades, it’s normal to have questions about what exactly is leaving your body and to wonder what it means for your health. Menstrual blood can change consistency from month to month for the same woman. Knowing what’s typical—and what’s not—can help you understand your body and see any warning signs.

What Should the Consistency Be?

Menstrual blood is different from the rest of your body’s blood. It doesn’t usually clot. If the blood clotted, it wouldn’t leave your body. So if this blood is different from the rest of your body’s blood, what should it look like? Some doctors say that the blood shouldn’t be too thin—like Kool-Aid—but it shouldn’t be too thick—like ketchup. The consistency should be somewhere in between.

However, that isn’t always the case. Here’s what it means if your menstrual blood is…

Thick and Clumpy

It’s normal for every woman to notice a clot of blood in the toilet bowl. This often happens during a heavier period. The CDC states that blood clots smaller than the size of a quarter are fine. But if you notice larger clots, it could be a sign of a hormonal imbalance (such as high estrogen and low progesterone) or a uterine fibroid, which is a small, benign growth inside the uterus.

In a study from the Birmingham Women’s Hospital, as many as 70% of women will have uterine fibroids before turning 50. They often don’t have negative consequences, but some can result in pain and pregnancy complications. If you notice large clots in your blood, talk to a health care provider to make sure everything’s all right.

Thin and Watery

Some women have lighter periods. But if your blood becomes thinner or watery or you experience a watery discharge of any color, it could be a symptom of anemia or a tumor. If your period blood gets thinner over two or three cycles, talk to your doctor about being tested for nutritional deficiencies or a fallopian tumor.

Slippery and Mucus-y

In the canal that leads to the uterus, cells produce mucus. This mucus helps protect and direct sperm to the egg, but it can also thicken when affected by hormonal contraceptives. If your menstrual blood is slicker than usual, that’s probably just because cervical mucus has mixed with the blood. This is normal and usually no reason for alarm. However, you know your body best. If anything seems unusual, make an appointment with your doctor.