Doctors Think Your Period Should Be a Fifth Vital Sign

Physicians are learning to ask more questions about periods to get a better understanding of a person’s overall health

An illustration of a woman holding a glowing tear drop.
Illustration: Sophi Gullbrants

ItIt happens monthly, for two up to seven days at a time. A woman will menstruate for about seven years during her lifetime, on average. And yet there are still plenty of unknowns and misunderstandings around the effect menstruation has on women’s health.

“There is tremendous variation in how girls and women think about menstruation and what they define as healthy and normal,” says Dr. Geri Hewitt, a professor of obstetrics/gynecology at Ohio State University, and a chair of the American College of Obstetrics and Gynecology (ACOG) adolescent health committee. “There is also tremendous cultural variation regarding expectations around menses.”

Some of the most persistent misconceptions about periods are that irregularity every month is normal, that super-heavy cycles are just part of “the curse,” that severe period pain is something everyone with a period experiences, and that you can’t get pregnant while menstruating. None of these are true.

The varying mores around periods means that a vitally important piece of information gets lost: That periods are a key indicator of women’s health.

This is due in large part to a lack of information. In the United States, menstruation is not always covered as part of sex ed classes — and comprehensive sex education is only taught in one-fifth of American middle schools. According to Hewitt, family members are usually the primary information source on periods, and that information can be incomplete or flawed: “If a mom had abnormal cycles or struggles with her menses, she may assume her daughter’s abnormalities are normal,” says Hewitt.

Periods are also stigmatized. A 2002 study found that people reported greater feelings of negativity toward a woman if they knew she was menstruating (the study had women accidentally drop a tampon out of their bag in front of people in the study). That stigma has knock-on effects within the scientific community, too: “Studies having to do with women’s health are less well funded due to cultural shame around menstruation,” says Hewitt.

The “fifth vital sign”

The varying mores around periods means that a vitally important piece of information gets lost: That periods are a key indicator of women’s health. Everything from their regularity or irregularity, lightness or heaviness, and associated pain or no pain can give doctors insight around a variety of health conditions — both those that involve fertility and those that have little to do with it.

That’s why a recently reaffirmed committee opinion by ACOG and supported by the American Academy of Pediatrics (AAP) advises health practitioners to consider periods the “fifth vital sign” — meaning menstruation is as important a health indicator as changes in body temperature, pulse, breathing rate, and blood pressure. First issued in 2015, and then reaffirmed in July 2019, ACOG’s directive serves as guidance to doctors — including those working outside of obstetrics and gynecology — about how to prioritize conversations about periods during an appointment.

“It is important for clinicians to have an understanding of the menstrual patterns of adolescent girls, the ability to differentiate between normal and abnormal menstruation, and the skill to know how to evaluate the adolescent girl patient,” says ACOG. “By including an evaluation of the menstrual cycle as an additional vital sign, clinicians reinforce its importance in assessing overall health status for patients and caretakers.”

Menstrual cycle changes or abnormalities can be a clear first symptom of a number of women’s health issues. “Regular cycles with the absence of excessive bleeding and/or pain are signs of wellness,” says Hewitt. “Any aberration is an indication for more investigation.”

Problems that can be signposted by irregular periods include: eating disorders; thyroid malfunction; hormone issues, including those that cause Polycystic Ovarian Syndrome (PCOS); sexually transmitted diseases; uterine lesions; and incorrect medication dosing. Very heavy periods, which are often dismissed, can indicate blood-clotting disorders. Excessive pain can suggest blockages, which can be hereditary.

For decades, the connection between menstruation and overall health was largely unrecognized. Primary caregivers and other non-OB-GYN physicians did not routinely ask about period details. Women didn’t always know how or when to bring period issues to doctors. “[People] may not report a problem because they didn’t know whatever they were experiencing was abnormal,” says Hewitt. While there’s still a lack of quality research on periods, scientists are filling the void. And the value of the period as an indicator of health overall is growing.

What’s healthy, and what’s a red flag?

Some irregularity in the first year of having a period is considered normal by gynecologists. That’s because it takes some time for the reproductive axis to mature: “The brain and ovary both need to mature and learn to sync with each other,” says Dr. Natalie Shaw, a pediatric endocrinologist and researcher at National Institute for Environmental Health Science (NIEHS). But this doesn’t mean that skipped cycles should be ignored — and any wonkiness should be limited to the first year.

The first year post-menarche is an important time for girls to learn what is healthy for them. Tracking should start right away, according to the physicians interviewed in this story, so that any irregularities can be identified. (In fact, all of them supported period-tracking apps for people of all ages.) Tracking allows girls and young women to build an understanding of their bodies and feel more comfortable talking about periods with doctors — like any other vital sign.

According to ACOG, a normal period doesn’t last more than seven days, though the time between periods can be anywhere from 21 to 45 days long. Once the period begins, it should occur at that interval from then on. Even one cycle where the period is 90 days apart or more is grounds for a follow-up. Using three to six pads or tampons per day is normal — changing a pad or tampon every hour or two is not and could indicate a bleeding problem. Extreme pain also shouldn’t be ignored, though cramps that can be treated with over-the-counter painkillers are okay. Like any vital sign measurement, there is room for some natural variation — but falling outside the ranges above means a closer check is important. As people grow older, get pregnant, miscarry, get an abortion, use IVF, have babies, switch birth-control types or devices, or breastfeed or not, changes in periods are often chalked up to hormonal fluctuations. All of these events can impact the monthly cycle. But, again, the same parameters apply.

More to learn

There’s still a lot for researchers to investigate. There are only a few available studies on periods, and most are old and contain small numbers of women, which doesn’t make for strong science. A 2008 study of just 10 girls’ hormone levels is the most current and commonly used study on first periods. That’s why in September 2019, Shaw launched the study, “A Girl’s First Period ― Why Is It So Unpredictable?” with the NIEHS.

It’s meant to be a small-scale yet very comprehensive study to build a stronger understanding of hormone patterns and menstrual cycle characteristics of adolescent girls. Current guidelines emphasize menstrual cycle length as the key data point for doctors to use to identify healthy menstrual cycles. Cycle length is a helpful data point, but Shaw says that’s “a statistical definition of normal, not a biological definition.”

It may seem strange for a doctor who is checking out, say, a broken ankle to ask about your period, but it shouldn’t be. “It’s just another way to ask about health.”

“It’s not based on any information about reproductive hormones such as progesterone, which is the primary marker of ovulation — the release of an egg,” she says. “We know from our previous study that girls with abnormal reproductive physiology can have ‘normal’ cycle lengths.”

According to Shaw, it’s abnormalities in hormone levels — not the length of the cycle — that matter most. How long, short, or irregular a cycle is often a symptom of the hormone changes that could indicate something is wrong.

“What I’m hoping to do is to establish what a normal developmental trajectory looks like, so that at some point we’ll be able to say with confidence — within a matter of months of a girl’s first period — ‘this girl is abnormal’, and try to do something about it then, rather than wait until she’s 18,” says Shaw, pointing to issues like infertility as well as risks for endometrial cancer or PCOS as conditions that could be identified earlier. “At that point, we’ve likely missed the critical window to intervene.”

Why early education is best

Most women with irregular periods in adulthood can trace them back to adolescence, according to the NIEHS. That’s exactly why the “fifth vital sign” movement is so important. Since periods can reflect other health problems, they should be asked about at any doctor’s visit, from primary care to an orthopedist to a dermatologist, says Dr. Cora Breuner, past chair of the Committee on Adolescence at the American Academy of Pediatrics.

It may seem strange for a doctor who is checking out, say, a broken ankle to ask about your period, but it shouldn’t be, says Breuner. “It’s just another way to ask about health.”

Here’s why: That broken bone could be the result of a bad fall — or it could be due to an eating disorder that’s only uncovered when a doctor or nurse asks about a woman’s last period and hears it’s missing. Menstruation often stops when a person isn’t eating enough; the body shuts down all but the vital processes. “Having normal periods means that your bones are in good shape. When periods stop she can develop bone mineral density or bone loss,” says Breuner. This is just one example of how a missing cycle can be a clue to the underlying cause of an injury or illness.

So far, much of the messaging around periods as the fifth vital sign is geared toward doctors. But some public health experts are starting initiatives to spread the word to young people. Kelsey Knight, a labor and delivery nurse practitioner, and Emily Varnam, a doula, have teamed up to teach “people who have periods” (recognizing that not all women have periods, and some men menstruate) to view their cycles as an important indicator of their health. Called The Fifth Vital Sign, the duo Kickstarted a tour of 43 U.S. states over a period of three months. Their two-hour class covers the basics of reproductive and endocrine systems, hormones, birth control methods and period-care products, and when and how to talk to a doctor about concerns, says Knight.

“We start with anatomy — assuming that people haven’t had this information but also recognizing that they are experts on their own experience,” says Varnam. “We talk about fertility indicators, and how the menstrual cycle is a vital sign for the body, while always affirming that people’s bodies are different.”

While they don’t give medical advice to the people who attend their classes, “we do point out what to look out for, like cervical fluid changes, a low basal body temperature, or heavy bleeding, so people can be better at advocating for themselves within the medical system,” says Varnam.

The idea that periods matter for health has the potential to not only help people identify health complications earlier, but also destigmatize the experience. Health care workers asking about periods can lead to other important information, like a lack of ability to pay for basics like pads or tampons. “If you run out of money for feminine hygiene products, are you using paper towels or napkins? That’s dangerous and can make you sick,” says Breuner. When doctors know about these challenges, they can step in and help provide the basics.

“It’s been impossible to talk about [periods] for hundreds of years without an eye roll. It’s stigmatized, it’s felt to be a sign of weakness, and feels dirty to many women and men,” says Bruener. “The more we talk about it, the quicker that bias will go away.”

AKA The Curious Human. Science journalist & nature nerd w/serious wanderlust. Former geologist. Still picks up rocks. Words in @NatGeo @SciAm @Slate @CNN, here.

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