Why Does My Period Blood Look Like That?

If you grew up conditioned to either consciously or subconsciously think of your period as something secretive or shameful—who among us has not scurried into a public restroom with a tampon up their sleeve?—you may throw your used tampon or pad into the trash or that little nameless bin without so much as a glance. But paying attention to the color and consistency of period blood can actually offer some helpful insights into your health and hormones.

The menstrual cycle is sometimes called the "fifth vital sign"—the other four vitals are body temperature, pulse rate, respiration rate and blood pressure—by doctors, including those at the American College of Obstetricians and Gynecologists (ACOG). It's an important marker of health, and yet the period is often overlooked, sidelined into a taboo topic.

"Women typically know their flow. If color [or] consistency changes significantly, there could be an underlying cause," said Alyssa Dweck, an OB-GYN and host of Business of the V podcast. Menstrual blood can actually tell you a lot about what's going on in your body—from hormonal imbalances to symptoms of endometriosis.

A reusable menstrual cup can help give a more accurate insight into the period blood's appearance, since it pools inside of a silicone or latex cone instead of being absorbed.

What your period color and texture is trying to tell you

According to Dweck, a thin, watery flow might indicate iron deficiency or anemia, whereas a super-heavy flow, especially one with clots, might suggest uterine fibroids or endometriosis. If a period is irregular or altogether absent, it could indicate a hormone imbalance called polycystic ovary syndrome or a thyroid irregularity.

Very heavy and dark

Almost purple in hue or clotty period blood can indicate excess estrogen, which also can cause fatigue and weight gain.

Pink and watery

Watery blood that's pink or lighter in color may indicate low estrogen, which could potentially affect fertility. Other signs of low estrogen include painful sex, frequent UTIs and headaches (which are also symptoms of perimenopause, or when the body transitions into menopause).

Brown and thick

Darker, almost brown, thick blood could potentially point to low progesterone or perimenopause. Low progesterone can make it difficult to carry a pregnancy to term, so if you've been struggling with miscarriage and notice dark, thick period blood, you'll want to tell your doctor about your periods.

Symptoms of PMS—like breast tenderness, extreme fatigue and severe cramping— can become extremely pronounced. Dweck recommends Midol, exercise and avoiding alcohol to help combat PMS when struggling with hormonal imbalance. Believe it or not, periods are not supposed to be excruciating, despite what we've been told our whole lives.

Of course, changes in color and texture are to be expected over the course of a normal flow, and "some small clots might be expected, especially upon awakening and standing after lying down for an extended period of time," Dweck added. Light-brown blood near the end of a cycle is typically not a cause for concern, as it's usually just older blood trickling out. If you notice deviation beyond what's normal for you, it's a good idea to check in with your doctor.

That said, what's "normal" will vary from person to person, but generally, "a typical period is a week or less of flow, red (light or deeper crimson) blood and less than a pad or tampon per hour," Dweck said. "Get to know your cycle, and you will learn what's healthy and normal for you individually."