When you go to the doctor, it’s routine to check vital signs: your pulse, body temperature, blood pressure, and respiratory rate. These measurements help paint a quick picture of how your body is functioning and detect potential health issues. But if you’re someone who menstruates, there’s another important indicator you should pay attention to — your period.

“All of our body parts, including our reproductive parts, are connected,” says Dr. Mary Rosser, an OB-GYN at New York-Presbyterian/Columbia University Irving Medical Center. “They each serve a different function, working together to keep the whole machine running.”

If you’re having mostly regular periods, it’s usually a good sign that your reproductive health and overall health is in check. But if your period is abnormal (for example, if it’s extremely painful or it’s missing altogether), it could be a clue that you may have some underlying health issues, says Dr. Rosser.

Health Matters spoke with Dr. Rosser to learn more about how your period can be considered a vital sign, and what can it tell you about overall health and potential underlying conditions.

What does a “normal” period look like for most people?
Your period (menstruation) occurs at the very beginning of your monthly cycle, which is made up of four phases: the menstrual phase, the follicular phase, the ovulatory phase, and the luteal phase. Most people who menstruate will get their period about every 28 days, but a full cycle can range from around 21 to 35 days.

Period symptoms vary from person to person, but common ones include:

• Pelvic cramps
• Bloating
• Sore breasts
• Irritability or mood changes
• Acne breakouts
• Headaches
• Fatigue
• Mood swings

What are some signs of an abnormal period?
A very heavy flow (needing to change pads or tampons every 1 to 2 hours, passing large clots, or bleeding longer than 7 days) may lead to fatigue or anemia (low iron levels), which can make someone feel tired, dizzy, or short of breath. Causes could include fibroids, hormonal imbalances, or other health issues.

A very light flow or missed periods might occur with stress, extreme exercise, weight changes, hormonal changes, or certain medical conditions. If it’s a big change from your usual cycle, it’s worth checking in with your clinician.

The color of menstrual blood can also vary: It can appear bright red, dark red, or brown at different stages of your period, and that’s normal. But if you notice unusual colors (like gray or orange), it could be a sign of infection and should be evaluated.

Changes in the usual pattern of your period — heavier or lighter bleeding, different timing, new pain, or other symptoms — are worth tracking and discussing with your healthcare provider. 

Is it normal for your period to change over the years?
Your menstrual cycle and period will naturally change as you reach different phases of life.

• Puberty: When you first start your period (usually between ages 9 to 15), it can be irregular for a few years. You might skip months or have heavier or lighter flow as your body adjusts to new hormone patterns.
• Adulthood: Periods usually become more regular in your 20s and 30s. Birth control, stress, weight changes, or medical conditions like PCOS or fibroids can still affect your cycle. If you’re not using birth control, your period can also be a sign of your fertility status.
• Pregnancy and postpartum: During pregnancy, your period stops. After birth, it can take weeks to months to return, especially if you’re breastfeeding. It might be different — heavier, lighter, or more irregular — before settling into a new pattern.
• Perimenopause (the transition to menopause): This can start in your 40s. Hormones begin to shift, and your periods might become closer together, further apart, heavier, lighter, or more unpredictable. Some people also notice more intense symptoms like hot flashes or mood swings.
• Menopause: Menopause is reached when you’ve gone 12 months without a period. After that, periods stop for good. Any bleeding after menopause should be evaluated.

What are some period symptoms that may indicate a health issue?
While it’s completely normal to experience some variety in your cycle each month, certain symptoms raise red flags:

• Bleeding for more than seven days
• Saturating a pad or tampon every one to two hours
• Lack of period for 90 days or more
• Bleeding mid-cycle (between periods)
• Bleeding after sex
• Extreme pain with cramping (not helped by over-the-counter pain medicine, causing nausea or vomiting, etc.)
• Excessive fatigue
• Shortness of breath

Talking about your period can feel taboo; and for that reason, someone might not realize that their period symptoms are out of the ordinary. It’s imperative that you see a doctor if you’re experiencing any of these symptoms, as they could indicate a serious underlying health condition.

What does it mean if you have an abnormal period?
Having an irregular or abnormal period doesn’t automatically mean that something is wrong. Your cycle, and your period, can change throughout your life due to a whole host of factors, such as weight gain, certain types of birth control, certain medications (such as antidepressants and anti-seizure medication), or menopause.

That said, if you’re having an irregular period or if your period disappears for 90 days or more, you should talk to your doctor. While it doesn’t mean that you definitely have one these issues, conditions that could lead to irregularity may include:

• Polycystic ovary syndrome (PCOS) 
• Endometriosis
• Fibroids
• Ovarian cysts
• Premenstrual dysphoric disorder, stress, or anxiety
• Ectopic pregnancy or miscarriage
• Sexually transmitted disease (STD)
• Eating disorders, excessive exercise, or underweight
• Thyroid disease
• Overweight or diabetes
• Premature ovarian failure
• Pelvic inflammatory disease (PID)

Speaking to a doctor will help you determine the cause of any issues or symptoms.

What are some ways to support menstrual health?
It can be very helpful to keep track of your period symptoms and cycle length; that way, you can compare month to month if something feels off. I recommend using a journal or a period tracking app to log when you get your period, how long it lasts, and any symptoms. By getting to know what is normal for you, you’ll be more easily able to recognize when something about your period is off.

You can also try cycle syncing. Cycle syncing involves eating healthfully, exercising, and getting enough sleep in order to support your body during each phase of your menstrual cycle.