How Is Menopause Diagnosed After a Hysterectomy?

Hi, I read your menopause article, and it said that the true sign to beginning menopause was the absence of a period for at least 12 months.  I have had a partial hysterectomy (I still have both ovaries), thus no longer have a period. My question is, how would I know if I am in menopause as I no longer have periods?

This is an excellent question that brings up a scenario that is not uncommon.  In women, a natural hormone that is produced by the brain, called follicle-stimulating hormone (FSH), normally encourages or "stimulates" the ovaries to mature to produce eggs.  After menopause, as the ovary shrinks and estrogen levels fall, the blood level of FSH rises gradually  in response to the falling estrogen levels.  The FSH level reaches a peak level at approximately 1-3 years.  As a result, menopausal women have a very elevated FSH level (about 30IU/L) that can be measured by testing the blood.

There are two reasons, however, why FSH levels are not used routinely to diagnose menopause in all women.  First, a woman's FSH level's can fluctuate very much during the transition period from day to day, so she may not always have elevated FSH levels.  Second, a woman has to be without a period for 12 months to be diagnosed as menopausal no matter what her FSH is, because that is the definition of menopause.

In the special situation of a woman who has had a hysterectomy, and therefore cannot rely on vaginal bleeding pattern, FSH levels may be helpful if they are elevated.  Unfortunately, there is no blood test that is perfectly reliable to diagnose menopause, either with or without a hysterectomy.