When should you worry about your menstrual cycle?

Abnormal vaginal bleeding can be a symptom of several gynecologic cancers, including cervical, endometrial (uterine) and vaginal. But if you’ve never had a regular menstrual period, you might not know what "abnormal" means. 

What constitutes a “normal” menstrual period? How many days should you expect to bleed, and how much time should elapse between each cycle? And, when should you be concerned enough about any irregularities to see a doctor? 

Read on for the answers to these questions and more. 

How long should a ‘normal’ menstrual period last?

Generally speaking, you should expect to bleed for between two and seven days during each period. Even if you stop and start within that timeframe — say, with a heavy flow for the first two, a steady tapering off for the next three, and then some moderate spotting on the last two (when you thought you were done) — that’s probably OK. But all of the bleeding should occur within that range. 

How much time should elapse between your cycles?

The average is around 28 days, which is right at four weeks. But if you can count between 21 and 35 days between each period, that would still be considered normal. 

Should I be concerned about heavy periods?

Not necessarily. Among other things, heavy periods could be due to: 

• Uterine fibroids: These benign tumors are also known as leiomyoma. 
• Adenomyosis: This is another benign condition in which endometrial tissues grow into the uterine wall. 
• Endometriosis: This is a benign but painful condition in which endometrial tissue grows outside the uterus. 

What’s “normal” will vary from person to person, of course, but your periods should at least be similar from one month to the next.  

What about menstrual cramps? Where do they fit in?

Menstrual cramps in and of themselves are not worrisome. But if you suddenly start to have them after never having had them before, that’s concerning. In that case, you should see a doctor. 

That being said, no one should have to live with debilitating pain. If you have severe menstrual cramps regularly, seek medical advice. There are many medications available that can help you feel better.  

When else should I see a doctor about my menstrual cycle?

If you haven’t begun menstruating yet by age 16, you haven’t established a fairly regular monthly cycle by then, or you are older than 55 and still experiencing vaginal bleeding, consult a gynecologist. 

You should also see a doctor if: 

• You’re bleeding every week for a couple of days. 
• You’re bleeding in bizarre patterns.  
• You’re bleeding only once every three or four months.  

None of these scenarios is considered normal, so they need to be investigated.  

That’s especially true since we’ve been seeing an increase in the number of endometrial cancer diagnoses, especially in women under age 50.  

Many of these women are only in their late 20s or early 30s, and they’ve never had normal periods. That means they’ve already logged about 15 years of irregular menstruation, depending on when they started. Often, the reason is because they are anovulatory — or not ovulating — and it’s never been recognized before or dealt with. That can increase your risk of both gynecologic cancers and precancerous conditions, so it’s important to get checked out. 

Why is not ovulating a problem? 

Ovulation is a normal part of the menstrual cycle that triggers a cascade of other processes in the body, including the shedding of the uterine lining. If your body doesn’t shed that lining regularly, it just keeps growing and building up. And, whether it’s due to polycystic ovarian syndrome or something else, that’s when you can start seeing precancerous changes or even actual uterine cancer develop. 

Don’t some contraceptives, such as birth control pills, IUDs and implants, prevent ovulation, too? 

Yes. But those devices also contain progesterone, a hormone that shuts down the endometrium. Progesterone thins out the existing lining, too, so it’s very protective against endometrial cancer. 

Can anything be done to reduce my risk of developing cancer due to menstrual irregularities?

Yes. Advocate for yourself. If you’re not having regular menstrual cycles, look into why not, and don’t stop until you get some answers.  

Something can usually be done to reduce your risk of developing cancer through proper hormone management. But you have to speak up for your doctors to know you have a problem. 

Larissa Meyer, M.D., is a gynecologic oncologist who specializes in the treatment of female cancers. 

Request an appointment at MD Anderson online or call 1-877-632-6789.