What is Estradiol?

Estradiol is the strongest of the three estrogens and an important player in the female reproductive system and the most common type for women of childbearing age. While men and women have estradiol, and it has a role in both of their bodies, women have much higher levels of the hormone than men.

What does estradiol do?

Estradiol has several functions in the female body. Its main function is to mature and then maintain the reproductive system. During the menstrual cycle, increased estradiol levels cause the maturation and release of the egg, as well as the thickening of the uterus lining to allow a fertilized egg to implant. The hormone is made primarily in the ovaries, so levels decline as women age and decrease significantly during menopause. Estradiol tests are used to help:

• Find out the reason for early or late puberty in girls

• Diagnose menstrual problems

• Find out the cause of infertility (the inability to get pregnant)

• Monitor infertility treatments

• Monitor treatments for menopause

• Find tumors that make estrogen

What other potential problems are connected to estradiol hormone levels?

In women, too much estradiol has been linked to acne, constipation, loss of sex drive, and depression. If the levels are extremely high, they can increase the risk of uterine and breast cancer as well as cardiovascular disease. Women with high estradiol levels may experience weight gain and menstrual problems.

If the body does not have enough estradiol, bone growth and development are slowed, and adults can develop osteoporosis (bone weakness). Girls may experience delayed puberty with low estradiol levels. Mood swings have also been connected to low estradiol levels.

How is estradiol and menopause related?

The effects of estradiol are clearly seen in women experiencing menopause. During this process, women naturally have lower levels of estradiol as the ovaries no longer produce it, causing the menstrual cycles to stop. This change often causes mood swings, vaginal dryness, hot flashes, and night sweats — the symptoms commonly associated with menopause. Over time, lower estradiol levels can lead to osteoporosis.

Until recently, most women going through menopause were treated with estradiol as a form of hormone replacement therapy (HRT) – usually by pill, gel, or patch – to help reduce the symptoms of menopause. While HRT is effective in improving these symptoms, recent studies have shown some risks associated with HRT, such as an increased risk of blood clots, heart disease and stroke, and breast cancer. Women interested in HRT should contact their medical provider, as factors such as age, lifestyle, and medical conditions can affect these risks. There are also non-hormonal options available to help with menopausal symptoms.

Why do I need an estrogen test?

You may need an estradiol test or an estrone test if you:

• Are having trouble getting pregnant

• Are a woman of childbearing age who is not having periods or having abnormal periods

• Are a girl with early or delayed puberty

• Have symptoms of menopause, including hot flashes and/or night sweats

• Have vaginal bleeding after menopause

What do the estradiol test results mean?

If your estradiol is higher than normal, it may be due to:

• A tumor of the ovaries or adrenal glands

• Cirrhosis

• Early puberty in girls

• Peri menopause (the years immediately before menopause)

If your estradiol or estrone levels are lower than normal, it may be due to:

• Primary ovarian insufficiency, a condition that causes a woman's ovaries to stop working before she is 40 years old

• Menopause

• Turner syndrome, a condition in which a woman's sexual characteristics don't develop properly

• An eating disorder, such as anorexia nervosa causing hypothalamic amenorrhea

• Polycystic ovary syndrome, a common hormone disorder affecting childbearing women. It is one of the leading causes of female infertility.