There are several hormone levels that physicians may suggest ordering. For health care providers (HCP) these may include estrogen (our own estradiol is what laboratories can measure), luteinizing hormone (LH) or follicle stimulating hormone (FSH). In general it is reassuring to have a test ordered because your doctor doing something and that makes us feel validated. However, if a test doesn't give a clear answer then it is a waste of the time and energy of everyone to do it, it is a waste of money for the health care system, insurers or for you personally.
Let me describe each of these potentially measured hormones in turn:
Estradiol should never be used to diagnosis perimenopause, primary ovarian insufficiency (POI) or menopause. The assumption is that it will be low if women have hot flushes (as both perimenopausal and menopausal women may). But night sweats start in women with regular periods and high estrogen levels (1). However, estradiol levels average 20% higher in perimenopause than in premenopausal women in both the follicular and luteal/premenstrual phases (2), are highly variable normally across the cycle and are extremely variable in perimenopause. Measuring estradiol in a normally menstruating woman is rarely or never needed since by definition, they will have normal levels! Also, if it happens that you go to the lab during flow or the first six days of your cycle, your estradiol may be low (as low as in menopause). That is normal during flow but often physicians don't know that!
LH should never be used to diagnosis perimenopause, POI or menopause.
If a woman has primary ovarian insufficiency (POI) and has had no period for three or more months, it is classically diagnosed by two FSH levels taken about a month apart. Both tests need to be higher than the upper limit of the premenopausal average for that lab (3). But that is a late sign since most with POI initially present just like perimenopause (heavy flow, cyclic night sweats, sleep disturbances etc.)(3). I would also say that FSH levels may not exclude the diagnosis of POI in a woman who is intermittently cycling. However, for the maximum likelihood of at least one of two being abnormally high, they should be timed to cycle days 2-4 as is sometimes used in perimenopause to assess a woman's potential success at in vitro fertilization.
FSH should not be used to diagnose perimenopause (4). Perimenopause must be diagnosed clinically. In women in their 30s or 40s with regular cycles but characteristic experience changes, I advocate using any three of nine characteristic changes (5).
FSH testing is not needed for menopausal women who are over age 40 or for women who have not had any menstrual flow for more than one year. Women are considered menopausal when they have not had a menstrual period for one year. It is more helpful for women who have had a hysterectomy to track any premenstrual or other cyclic changes. When there are no cyclic changes over the year, she will know she is now likely menopausal.
If your HCP suggests ordering a battery of urinary or salivary testing, CeMCOR suggests that you consider declining, based on the general lack of validation, high cost and the current confusion of methods.. It is preferable to use tools that don't rely on hormones measured at a single point in time (since hormone levels are pulsatile and go up and down) but rather on things your body can tell you. For example, clear, stretchy cervical mucus that stretches in a thread longer than 3 cm or one and a half inches and lasts longer than 3 days means high estrogen levels. Also, any front-of-the breast soreness means a higher-than-usual or a midcycle peak estrogen level.
Quantitative basal temperature is an easy and validated way for reasonably regularly menstruating women to assess ovulation and the luteal phase length.
(1) Hale GE, Hitchcock CL, Williams LA, Vigna YM, Prior JC. Cyclicity of breast tenderness and night-time vasomotor symptoms in mid-life women: information collected using the Daily Perimenopause Diary. Climacteric 2003; 6(2):128-139.
(2) Prior JC. Perimenopause: The complex endocrinology of the menopausal transition. Endocr Rev 1998; 19:397-428.
(3) Rafique S, Sterling EW, Nelson LM. A new approach to primary ovarian insufficiency. Obstet Gynecol Clin North Am 2012; 39(4):567-586.
(4) Burger HG. Diagnostic role of follicle-stimulating hormone (FSH) measurements during the menopausal transition--an analysis of FSH, oestradiol and inhibin. European Journal of Endocrinology 1994; 130:38-42.
(5) Prior JC. Clearing confusion about perimenopause. BC Med J 2005; 47(10):534-538.