Q. I’m 40, and I still have irregular periods. Is this normal?

Teraona Low Dog, MD, is the director of the fellowship for the Arizona Center for Integrative Medicine at the University of Arizona School of Medicine.

A.First off, keep in mind that regular is relative. Many women believe that if their periods don’t come every 28 days, something is wrong with them. But if you have a consistent cycle of 35 or even 40 days, that’s normal for you. That said, roughly 30 percent of women have irregular periods at some point, and some fluctuation is fine—during puberty, perimenopause, and after pregnancy or breast-feeding. Even women with regular menses can skip a cycle now and then due to stress, travel, or other hiccups in their routine, and it’s nothing to worry about.

But if you’re going months without menstruating or feel like you never know when your period will come, that’s irregular. If you haven’t already, you should see your doctor and get checked for abnormalities that could affect your cycle—hormonal imbalances caused by a thyroid problem and polycystic ovary syndrome (PCOS) are the most common. Even tiny disruptions in prolactin, cortisol, or other hormones can disrupt a woman’s menstrual cycle. An overactive thyroid can cause scant or absent periods, while an underactive thyroid can lead to irregular cycles with heavy bleeding.

By and large, the most common reason for persistent irregularity is PCOS. Characterized by an excessive amount of estrogen and androgen (male hormone), coupled with insulin resistance, PCOS leads to anovulation (failure to release an egg from the ovary) and irregular menses. Women with PCOS may have cysts (typically small and benign) on their ovaries, acne, and excessive hair growth on the chin or upper lip; they may also be overweight, obese, or have difficulty getting pregnant. It also increases your risk for developing estrogen-driven cancers (breast and uterine), heart disease, and diabetes due to long-term exposure to high levels of insulin.

Sounds serious, but you can get your cycle back on track (and even treat PCOS) with diet, exercise, weight management, and herbs.
Healthy diet, healthy cycle
Eating the right foods and supplementing for optimal nutrient absorption can help you get regular. Some guidelines:
Follow a low-glycemic, low-fat diet, and reduce your intake of refined carbohydrates. This helps to reduce insulin resistance—one of the main drivers of anovulation and hormone imbalance—and is especially important if you have PCOS.
Take a multivitamin, and make sure you get the daily requirements for calcium, magnesium, and vitamin D. While these supplements won’t correct your menstrual irregularity, studies show that women with infrequent, irregular periods may be at greater risk for osteoporosis later in life.
Take an iron supplement with vitamin C (to enhance iron absorption) if your doctor says you’re anemic. If you bleed heavily or for longer than the normal three to five days, you may be at risk for anemia.

The stress factor
Since stress can be a major component of menstrual irregularity, it’s a good idea to invest in these remedies and actions:
Aromatherapy oils to soothe tension. Add a few drops of lavender, clary sage, chamomile, neroli, or ylang-ylang to a warm bath at the end of a trying day.
Take 15 minutes every day for your-self. Whether it’s relaxing on the couch, watching a favorite show, reading a book, or listening to a great CD, don’t feel guilty about taking some “me” time.
L-theanine, an amino acid extracted from green tea, reduces anxiety and enhances relaxation without causing drowsiness. Take 100 to 200 mg daily.
Regular exercise reduces stress and improves your overall health. But don’t overdo it. When a woman works out a lot and has a low body weight, estrogen levels fall, and periods become irregular or stop altogether. Make sure that you keep your caloric intake in sync with your caloric expenditure to maintain a stable weight. However, women with PCOS who are overweight will regain normal ovulatory cycles with only a 10 percent loss of body weight. Invest in a pedometer, and walk 10,000 steps every day.

Herbal method
Herbs have been used for generations to correct menstrual imbalances. Try each of these remedies individually for at least three to six months. If you don’t see any improvement, stop and try another formula, or consult an herbalist to find something that will work for you.
Chaste tree fruit (Vitex agnus castus) has a progesterone-like effect, which makes it particularly useful for teenagers and women transitioning through perimenopause, as well as women with occasional menstrual irregularity and strong PMS­. However, it’s not ideal for women with PCOS. A number of small studies show that chaste tree helps regulate prolactin—elevated levels can cause irregular periods—and normalize your menstrual cycle when taken for at least three months. Take 250 to 500 mg of powdered chaste tree or 20 to 40 mg of chaste tree extract each morning.
White Peony (Paeonia lactiflora) has been shown to be particularly effective in balancing hormonal abnormalities in PCOS. Take 2 to 4 grams three times a day.
Shatavari (Asparagus racemosus), meaning “she who possesses a hundred husbands,” has a long history as a female tonic and is often used for treating irregular menstruation and anovulation. As a rejuvenating tonic, it also helps if you feel debilitated, drained, and tired from PCOS or stress-related irregularity. Take 1 to 2 grams three times per day.