What Hormone Imbalance Tests Reveal About Women's Health

Hormone blood tests can reveal an abundance of important information about a woman's health. Levels of estrogen can reveal where a woman is in her menstrual cycle, for example, which can help pinpoint the cause of fertility problems or signal the onset of menopause.

Blood tests to measure female hormone levels also can play a role in diagnosing medical conditions such as thyroid disease or diabetes, and they can help evaluate how well a medication is working.

The female hormones typically evaluated—often as part of a comprehensive hormone panel in which more than one hormone is tested—are:

• Estrogen
• Progesterone
• Follicle-stimulating hormone (FSH)
• Testosterone/DHEA
• Thyroid hormones

This article will look at each of these tests in detail, when they're needed, and what their results could mean.

Estrogen

Estrogen is not a single hormone, but rather a group of three hormones:

• Estrone (E1)
• Estradiol (E2)
• Estriol (E3)

Of these, estradiol is the major sex hormone responsible for, among other things, sexual functioning, healthy bones, and female characteristics. Estradiol is produced mainly by the ovaries.

Estradiol levels vary throughout the menstrual cycle and are highest at ovulation and lowest at menstruation. They decrease slowly with age; the largest drop occurs at menopause when the ovaries "switch off."

You may need an estrogen test if you have symptoms of an estrogen-related condition or:

• You're having trouble getting pregnant
• You're skipping or having abnormal periods
• Your puberty appears to be delayed, regardless of biological sex
• You're having menopause symptoms
• You have vaginal bleeding after menopause
• You're biologically male but displaying female characteristics (e.g., developing breasts)

Low estrogen levels may be a sign of:

• Polycystic ovary syndrome (PCOS)
• Decreased pituitary function (hypopituitarism)
• Low testosterone (hypogonadism)
• Anorexia nervosa
• Low body fat

Certain medications, such as Clomid (clomiphene), also can cause a decline in estrogen levels.

High estrogen levels may occur with conditions such as:

• Obesity
• Light or heavy menstrual bleeding
• Worsened premenstrual syndrome
• Fatigue
• Loss of sex drive

Certain medications, including steroid hormones, phenothiazines, tetracycline antibiotics, and ampicillin, also are known to increase estrogen levels.

Progesterone

Progesterone is produced by the ovaries during ovulation. Its function is to help prepare the uterus to receive a fertilized egg.

When an egg is released from an ovary during ovulation, the remnants of the ovarian follicle (the corpus luteum) release progesterone along with small amounts of estradiol. If the egg isn't fertilized, the corpus luteum breaks down, progesterone levels plummet, and a new menstrual cycle begins.

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

You may need a progesterone test to determine:

• Whether you're ovulating normally
• Why you're having trouble getting pregnant
• The risk of miscarriage or other complications of pregnancy
• If you have an ectopic pregnancy (outside of the uterus)

Low progesterone levels during pregnancy often foreshadow miscarriage and premature labor. You may be given a synthetic form of progesterone to prevent the early onset of labor.

High progesterone levels are of little medical consequence unless they're persistent, which may indicate an increased risk of breast cancer.

Follicle Stimulating Hormone

Follicle-stimulating hormone (FSH) is produced by the pituitary gland. It can be evaluated with either blood or urine tests, which can look at either a single sample or, in order to detect fluctuations in FSH, several samples taken over 24 hours.

FSH stimulates the growth of an egg (follicle) in the ovary to get it ready for fertilization. As estrogen and other hormone levels begin to decline—as the ovaries lose their reproductive potential—the pituitary gland will produce more FSH to compensate for this loss.

In adult biological females, the FSH test may be used to evaluate conditions such as:

• Abnormal menstrual bleeding
• Infertility
• The start of perimenopause or menopause
• Ovarian function and PCOS
• Pituitary gland tumors
• Ovarian cysts

Abnormal FSH levels are often caused by a disease or congenital defect of the hypothalamus or pituitary gland, or the hypothalamic-pituitary-ovarian axis.

FSH tests are sometimes performed on biological men and children, as well.

Testosterone/DHEA

Although testosterone typically is regarded as the "male sex hormone," it's also part of the female hormonal make-up. In fact, testosterone is the precursor of estradiol—most of the testosterone produced in the ovaries and adrenal glands is converted to estradiol with the help of an enzyme called aromatase.

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

You may need a testosterone or DHEA test because of:

• Irregular or missed periods
• Possible ovarian disorders
• Weight gain
• Acne
• Development of male traits (excess hair growth, male pattern baldness, deepening voice)
• Infertility
• Decreased sex drive

All of those are consequences of high testosterone except for decreased sex drive, which can indicate low levels and is common during perimenopause.

PCOS, ovarian cancer, and anabolic steroid abuse are common causes of high testosterone levels.

Thyroid Hormones

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

• 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

Thyroid function is often included in a female hormone panel because thyroid diseases are more common in women than men. It may also be included to assess the impact of thyroid function on fertility and pregnancy.

You may need a thyroid hormone test to look for symptoms of high thyroid hormones, called hyperthyroidism, or symptoms of low thyroid hormones, called hypothyroidism.

Hyperthyroidism symptoms include:

• Anxiety
• Weight loss
• Tremors
• Rapid heart rate
• Bulging eyes
• Goiter
• Hyperactivity
• Irregular and/or light menstrual periods

Symptoms of hypothyroidism include:

• Fatigue
• Weight gain
• Frequently feeling cold
• Hair loss
• Irregular periods
• During pregnancy, preeclampsia, placental abruption, miscarriage, preterm birth, low birth weight, and congenital thyroid problems

Frequently Asked Questions

When should you get a hormone blood test?

If you have symptoms of a possible hormonal imbalance, you might need to get a hormone blood test. According to the Society for Endocrinology, it's usually best to have your blood drawn for a hormone test in the first half of your menstrual cycle, because levels are more distinct at that time. However, if you're having a progesterone test to see if you're ovulating properly, it will likely be measured on day 21 of your cycle, which is in the middle of the second half.

How early can a blood test detect that you're pregnant?

Hormonal blood tests performed by a medical facility can detect pregnancy earlier than home pregnancy tests using urine. Blood tests can detect pregnancy between six and eight days after you ovulate. By contrast, home pregnancy tests should be taken after your period is late, which is between 12 and 16 days after ovulation. Waiting until this point can help you avoid false negatives or positives.

A Word From Verywell

Hormones have a big impact on your health, especially when it comes to anything related to reproduction. If you're having health or infertility issues that you think could be related to a hormonal imbalance, talk to your doctor. Simple blood tests may be able to reveal what's going on and help you find the right treatments.