If you're over 45 and you're pushing past 35 days, it may be because you're perimenopausal and beginning to ovulate less frequently. According to another recent study, as women age from their 20s through their early 40s, the average menstrual cycle declines from 30 to 27 days (though many women had cycles that were longer or shorter). This average increases as you approach menopause: up to 35 days when you're three to four years away, then 45 days two years prior to the change, and finally 80 days in the year before you stop altogether.
Talk to your doctor if you're younger than 45. Also if you're suddenly vacillating a lot more than is typical for you. "If you have a 14-day cycle followed by a 36-day cycle, that's usually an indication that you have a hormone imbalance," says Mary Jane Minkin, MD, clinical professor of obstetrics and gynecology at Yale University School of Medicine. You should have your ob-gyn check for an underlying cause, especially if you're still at an age where you might want to get pregnant.
If you're not pregnant, your ovaries are probably failing to release an egg (anovulation), which means your body won't produce the hormones that guide menstruation. Stress can trigger anovulation, and doctors don't typically worry if it happens just once or twice a year. In older women, a "missed" period may also simply be a very long cycle. Experts say that when you see a 60-day cycle, that's a good indication you're approaching menopause.
Talk to your doctor if you miss more than two periods (and you're not perimenopausal) or have other symptoms such as irregular bleeding. Polycystic ovary syndrome (PCOS) occurs in about 10 percent of women of childbearing age (women who are obese or have insulin resistance seem to be at higher risk). This condition can cause extreme hormonal swings, missed periods, infertility, thinning hair, and other health concerns.
It's most likely due to progesterone levels fluctuating more—or less—than is typical; stress, lack of sleep, starting a diet—any number of events can influence progesterone. And that will alter your period: "Estrogen is the fertilizer that grows the uterine lining each month, and progesterone is the lawn service that keeps it in check," says Minkin.
Talk to your doctor if you have two or more successive months of heavy bleeding. You may need progesterone therapy. Heavy bleeding can also be a sign of endometriosis, a condition in which uterine tissue grows outside the uterus. Benign growths called fibroids occur in at least a quarter of women and can cause heavy bleeding and pelvic pain. Very light bleeding, on the other hand, can be a sign of a thyroid condition like Graves' disease, especially if you also have fatigue and weight loss.
Your body could be generating excess prostaglandins, hormonelike chemicals that trigger the uterus to contract during menstruation and labor. Menstrual cramps are extremely common, and they can worsen when you're under stress. A poor diet, especially one with too much salt, sugar, alcohol, or caffeine, may also ramp up the pain. On occasion, you can try a double dose (800 milligrams) of ibuprofen if you've been struck with cramps.
Talk to your doctor if the ibuprofen won't dull the pain or if your killer cramps are accompanied by other unusual changes like excess bleeding or irregular periods. Endometriosis and fibroids can also lead to particularly painful periods.
From heavy bleeding to unpredictable periods, low-dose birth control pills can tame even the most mischievous menstrual cycles, says Mary Jane Minkin, MD, co-author of A Woman's Guide to Menopause and Perimenopause. "They take your ovaries out of the picture and artificially control your cycles, eliminating many of the unpleasant symptoms of hormonal fluctuation," says Minkin. "They also provide contraception, which is important. Women forget they can still get pregnant when they're perimenopausal and have erratic cycles. I've delivered the babies of three 47-year-olds who were not planning on getting pregnant." You can safely stay on the Pill until you reach menopause as long as you don't smoke.