Doctor K: Woman, 40, questions lack of menstruation

DEAR DOCTOR K: I have not had my period for three months. I’m not pregnant and I’m only 40, so I’m too young for menopause. What’s going on?

DEAR READER: What you’re experiencing sounds like secondary amenorrhea. I say that because you’ve menstruated in the past, you’re not old enough to be entering menopause, and you’ve stopped menstruating for three or more consecutive months. That’s the definition of secondary amenorrhea.

Having regular menstrual periods requires the normal production of sex hormones in the brain (the hypothalamus and pituitary gland). These sex hormones travel through the blood to the ovaries. Sex hormones produced by the ovaries are what tell the uterus to go through the changes that lead to monthly periods – and allow you to conceive a child. So, problems in the brain, the ovaries or uterus can all cause secondary amenorrhea. There are other conditions that don’t apply to you that can stop menstrual periods. Chemotherapy for cancer can at least temporarily affect the ovaries and lead to secondary amenorrhea. So can breast feeding.

Finally, there’s a condition that might apply to you. About one in 100 women who are age 40 get what’s called premature ovarian failure. Their ovaries suddenly stop making sex hormones and stop releasing eggs each month. The causes of this condition are largely unknown, but we do know that autoimmune diseases are associated with the condition.

To figure out the reason for your loss of regular menstrual periods, check with your doctor. You’ll be asked questions about your typical menstrual patterns, rapid weight changes, birth control methods, exercise regimen, stress in your life and the medications you are taking. The doctor may also do blood and urine tests or a noninvasive pelvic ultrasound. Finally, your doctor may want to recheck to make sure you’re not pregnant.

In most cases, the treatment depends on the cause of the amenorrhea.