What is E2?
Estradiol is primarily a female sex hormone and is mainly produced by the ovaries. It is also produced by the breasts, adrenal glands and placenta, during pregnancy. In males, it is produced in very small amounts by the testes and plays a role in the development and growth of bone. In females, it plays an important role in the growth and development of the sex organs which includes, the uterus, fallopian tubes, breasts, and vagina. It also plays an important role in regulating the distribution of body fat and to maintain the bone and joint health. The estradiol test measures the levels of estradiol in the blood and is also known as the E2 test.
Why is E2 done?
To diagnose hypogonadism (production of fewer sex hormones) in females
To evaluate the cause of oligomenorrhea (infrequent menstruation) and irregular menstruation in females
To evaluate the cause of feminization in males like gynecomastia (enlarged breasts)
To evaluate the cause of precocious (early) and delayed puberty in females
To evaluate the symptoms of menopause like abnormal vaginal bleeding
To monitor follicle development in case of infertility in women
To monitor treatment in case of hormone replacement therapy taken by women after menopause
To evaluate the lack of secondary sexual features, lack of muscle mass, delayed puberty in males
What does E2 Measure?
Estradiol test measures the levels of estradiol in blood. Estradiol is a form of estrogen hormone which plays an important role in the function and development of reproductive organs and in the formation of secondary sex characteristics in females. It regulates the menstrual cycle in women along with progesterone. Other functions of estrogen along with progesterone include the growth of breasts and uterus. Estrogen hormone is also found in men. It regulates growth and metabolism in both males and females. In men, estradiol is produced in testicles while in pre-menopausal women it is produced in ovaries. In postmenopausal women, estradiol is converted into estrone. Estradiol is present in high levels in non-pregnant and pre-menopausal women. Depending upon the age of the women and her reproductive status the values of estradiol varies. It is considered to be one of the good markers as regards to ovarian function.
At birth, the levels of estradiol are high but the levels fall within a few days and become minimal during early childhood. As puberty approaches the levels of estradiol rise. During the menstrual cycle, its levels vary depending upon the ongoing menstrual cycle phase. During menopause, the levels of estradiol fall as the production by ovaries decreases.
Interpreting E2 results
High levels of Estradiol may indicate:
Puberty before time (precocious puberty) in girls
Ovarian tumors in females
Tumors of adrenal glands in men and women
Gynecomastia (enlarged breasts) in men
Delayed puberty in males
Hyperthyroidism in men and women
Cirrhosis in men and women
Low levels of Estradiol may indicate:
Hypogonadism in females (the abnormal function of ovaries)
Conditions in which female sexual characteristics are underdeveloped like Turner’s Syndrome