Hormone Blood Tests for Women

There are times when a comprehensive hormone panel may be ordered to help identify hormonal imbalances in women, either to diagnose disease, monitor treatment, or characterize a woman's reproductive status. Depending on the aims of testing, one or several hormones may be evaluated.

Female hormones play a vital role in the sexual development, reproduction, and general health of women. The hormone levels naturally change over time (most significantly during puberty, pregnancy, and menopause) but can also be affected by illness, environment, and medications.

Here are 5 female hormones commonly include in a comprehensive panel:

Estrogen is a group of hormones that includes estradiol, estriol, and estrone. Of these, estradiol is the major sex hormone responsible for, among other things, sexual functioning, healthy bones, and female characteristics. 

In premenopausal women, estradiol is made mainly by the ovaries. The levels will vary throughout the monthly menstrual cycle, with the levels highest at ovulation and lowest at menstruation. Estradiol levels reduce slowly with age with the largest decrease occurring at menopause when the ovaries "switch off."

Low estrogen levels may be a sign of polycystic ovarian syndrome (PCOS), low pituitary function (hypopituitarism), low testosterone (hypogonadism), anorexia nervosa, or low body fat. Certain medications, such as Clomid (clomiphene), can also lower estrogen levels.

High estrogen levels may occur with conditions such as obesity, diabetes, high blood pressure, and with the use of certain medications, including steroid hormones, phenothiazines, tetracycline antibiotics, and ampicillin.

Progesterone is a hormone produced by the ovaries during ovulation which helps to prepare the uterus to receive a fertilized egg.

When an egg is released from the ovary during ovulation, the remnants of the ovarian follicle (called the corpus luteum) will release progesterone and, to a lesser extent, estradiol. If the egg is not fertilized, the corpus luteum will break down, progesterone levels will plummet, and the new menstrual cycle will begin.

If the egg is fertilized, progesterone will stimulate the growth of blood vessels that supply the endometrium (the lining of the womb). At the same time, progesterone stimulates glands in the endometrium to secrete nutrients to nourish the developing embryo.

Low progesterone levels during pregnancy often foreshadow miscarriage and premature labor. Mothers at risk of preterm birth may be given a synthetic form of progesterone to delay the onset of labor.

Progesterone levels may be measured to help pinpoint the cause of infertility, assess the risk of miscarriage, or diagnose an adrenal disease or certain types of cancer.

Progesterone, taken either alone or in combination with estrogen, is commonly used as an oral contraceptive ("the pill"). Oral contraceptives work by preventing ovulation, making them 99.7 percent effective in preventing pregnancy, according to the Centers for Disease Control and Prevention.

Follicle-stimulating hormone (FSH) is produced by the pituitary gland. It stimulates the growth of an egg (follicle) in the ovary to get it ready for conception.

As estrogen and other hormone levels begin with decline—during menopause or diminished ovarian reserves (when the ovaries lose their reproductive potential)—the pituitary gland will produce more FSH to compensate for this loss.

The FSH test may be used to evaluate conditions such as abnormal menstrual bleeding, infertility, menopause, PCOS, pituitary gland tumors, and ovarian cysts.

If your FSH is too high, it is usually because the ovaries are malfunctioning; the problem rarely lies with the pituitary gland. On the other hand, low FSH levels are often caused by a disease or congenital defect of the hypothalamus, pituitary gland, or adrenal glands (referred to as the hypothalamic-pituitary axis).

Even though people recognize testosterone as the "male sex hormone," it is also produced in women. The ovaries and adrenal glands are the main sources of testosterone, most of which will be converted into estradiol using an enzyme known as aromatase.

High testosterone levels may result in irregular or missed menstrual periods, weight gain, excess body hair, acne, infertility, deepening of the voice, and male-pattern hair loss. These secondary male traits are commonly referred to as virilization.

Low testosterone may occur during menopause, resulting in a significantly decreased sex drive (libido). 

Like testosterone, dehydroepiandrosterone (DHEA), is classified as an androgen. An elevated DHEA level may occur with conditions such as congenital adrenal hyperplasia or cancer of the adrenal gland.

Thyroid function is measured and characterized by a group of hormones produced by the pituitary gland or the thyroid gland itself. The three main types include:

• Thyroid-stimulating hormone (TSH), a pituitary hormone that signals the thyroid gland to produce more or less hormone
• Thyroxine (T4), a "storage" hormone that needs to be converted to an active state
• Triiodothyronine (T3), the "active" thyroid hormone created from the conversion of thyroxine

Elevated thyroid hormones (hyperthyroidism) may cause weight loss, goiter, hyperactivity, and Irregular and/or light menstrual periods in women.

By contrast, low thyroid hormone (hypothyroidism) during pregnancy can lead to preeclampsia, placental abruption, miscarriage, preterm birth, low birth weight, and congenital thyroid problems.