Testosterone and Estrogen Levels

Hormones are chemical messengers in your body. They are produced by your glands and enter the bloodstream. There are more than 50 different types of hormones. As they circulate throughout your body, they regulate various bodily functions, including growth, metabolism, reproduction, and mood.

Estrogen in Women

Estrogen is a group of related hormones that comprises estriol, estradiol, and estrone.

• The placenta produces estriol during pregnancy.

• Estradiol is the main sex hormone in premenopausal women and individuals AFAB. Premenopause refers to the period from your first menstruation until you reach perimenopause, the phase just before menopause. Estradiol is derived from developing ovarian follicles and is responsible for female characteristics and sexual function. It also plays a crucial role in bone and cardiovascular health.

• Estrone is the predominant estrogen during and after menopause.

Estrogen levels fluctuate throughout your life. During puberty, estrogen levels surge to facilitate physical changes like breast development. Levels vary during the menstrual cycle, increasing during ovulation when an egg is released, and decreasing during menstruation. They also decline as you approach and undergo menopause.

Normal estrogen levels

After menstruation begins, the principal type of estrogen in your body (except during pregnancy) is estradiol. Normal levels are:

• 30 to 400 picograms per milliliter (pg/mL) if you have not yet undergone menopause 

• 0 to 30 pg/mL if you are postmenopausal

Low Estrogen Levels in Women

There are several reasons your estrogen levels may decrease. Some of these include:Hypogonadism. This condition can cause your ovaries to reduce or cease estrogen production. It can be congenital or develop later due to injury, infection, or other factors. 

Hypopituitarism. Your pituitary gland is essential for your ovaries to produce estrogen. If there is an issue with your pituitary gland, estrogen production decreases. 

Perimenopause and menopause. During perimenopause (the phase preceding menopause) and menopause, your estrogen levels (especially estradiol) decline significantly. This also occurs if your ovaries are removed or damaged before age 40, leading to early menopause.

Polycystic ovary syndrome (PCOS). This condition causes cysts on your ovaries, which can lead to menstrual irregularities and infertility. Various hormonal changes occur with PCOS, including low estrogen.

Anorexia nervosa (eating disorder). With an eating disorder such as anorexia or bulimia, your body may lack the nutrients necessary to maintain adequate estrogen levels.

Low estrogen levels may also result from certain medications. For instance, some breast cancer treatments involve inhibiting estrogen production. Levels may also be low immediately after childbirth and during breastfeeding.

Why are female athletes and athletes AFAB at risk for low estrogen levels?

Women and individuals AFAB with low body fat often produce insufficient sex hormones. This can cause irregular or absent periods, as well as osteoporosis -- thinning bones -- and fractures.

Estrogen Levels and Menopause

Menopause is a natural transition for all women, characterised

by a decrease in estrogen levels. It can also occur suddenly in younger women whose ovaries are removed, leading to "surgical menopause."

On average, menopause occurs at age 51. During menopause, your body produces less estrogen, which can cause uncomfortable symptoms, including:

• Hot flashes

• Night sweats

• Vaginal dryness or itching

• Loss of libido or sex drive

• Mood swings

Lower estrogen levels may also increase the risk of heart disease and osteoporosis.

High Estrogen Levels in Women

During puberty, elevated estrogen levels are normal, as this hormone drives changes in a young girl's body. It contributes to the development of breasts, fuller hips, and pubic and underarm hair. Estrogen levels also increase during a healthy pregnancy.

Other factors that can lead to high estrogen levels include:

• Having high body fat

• Undergoing hormone therapy

• Stress

• Excessive alcohol consumption

• Liver issues

Symptoms of high estrogen include irregular periods and dense breast tissue.