Estradiol is a form of estrogen produced in the ovaries and released from the ovaries, adrenal cortex and placenta during pregnancy. Abnormal estradiol levels can indicate a problem with the reproductive organs or the adrenal glands. An estradiol test is a blood test most commonly used to evaluate ovarian function.
Estrogen functions as the main sex hormone for females. Estradiol is among the most common forms of estrogen, alone with estrone and estriol. Estradiol is especially important in the menstrual cycle, working in conjunction with follicle-stimulating hormone, luteinizing hormone and progesterone. In addition to controlling ovulation and conception, estradiol helps promote healthy bone structure and regulation of cholesterol levels, according to Lab Tests Online.
Low Estradiol Levels
Low estradiol levels may indicate ovarian failure or low estrogen production as a result of rapid weight loss or low body fat. Low estradiol levels may also indicate Turner syndrome, a genetic condition that occurs when a female does not have the usual two X chromosomes. Turner syndrome can produce symptoms such as drooping eyelids, dry eyes, infertility, absence of menstruation, incomplete development during puberty and short stature. If a physician suspects Turner syndrome, genetic testing can confirm a diagnosis.
High Estradiol Levels
High estradiol levels often indicate an ovarian tumor. Such tumors aren't necessarily an indication of ovarian cancer, since tumors may be cancerous or noncancerous. Older women are at the highest risk for ovarian cancer, according to the American Cancer Society; about half the women diagnosed with the disease are 60 or older.
If a physician notes that a patient has abnormal estradiol levels, she will often order follow-up testing. If estradiol levels are low, the patient may undergo further blood tests, genetic testing or imaging studies to determine the cause. If estradiol levels are elevated and an ovarian tumor is suspected, the next step may be imaging studies or exploratory surgery.
Estradiol levels are usually taken as a panel with other estrogen levels. Lab Tests Online explains that many factors can affect the estrogen levels in the body, such as illness, hypertension, anemia and impaired liver and kidney function. Some medications, such as glucocorticosteroids, estrogen-containing drugs and tetracycline, may also increase estrogen levels.