Estrogen
Estrogen | The Primary Sex Hormone
Estrogen is probably the most widely known and discussed of all hormones. The term “estrogen” actually refers to any of a group of chemically similar hormones: estrone, estradiol (the most abundant in women of reproductive age) and estriol. Overall, estrogen is produced in the ovaries, adrenal glands and fat tissues. More specifically, the estradiol and estrone forms are produced primarily in the ovaries in premenopausal women, while estriol is produced by the placenta during pregnancy.
Other Roles of Estrogen
Bone
Estrogen produced by the ovaries helps prevent bone loss and works together with calcium, vitamin D and other hormones and minerals to build bones. Osteoporosis occurs when bones become too weak and brittle to support normal activities.
Your body constantly builds and remodels bone through a process called resorption and deposition. Up until around age 30, your body makes more new bone than it breaks down. But once estrogen levels start to decline, this process slows.
Thus, after menopause your body breaks down more bone than it rebuilds. In the years immediately after menopause, women may lose as much as 20 percent of their bone mass. Although the rate of bone loss eventually levels off after menopause, keeping bone structures strong and healthy to prevent osteoporosis becomes more of a challenge.
Vagina and Urinary Tract
When estrogen levels are low, as in menopause, the vagina can become drier and the vaginal walls thinner, making sex painful.
Additionally, the lining of the urethra, the tube that brings urine from the bladder to the outside of the body, thins. A small number of women may experience an increase in urinary tract infections (UTIs) that can be improved with the use of vaginal estrogen therapy.
Perimenopause: The Menopause Transition
Other physical and emotional changes are associated with fluctuating estrogen levels during the transition to menopause, called perimenopause. This phase typically lasts two to eight years. Estrogen levels may continue to fluctuate in the year after menopause. Symptoms include:
- Hot flashes—a sudden sensation of heat in your face, neck and chest that may cause you to sweat profusely, increase your pulse rate and make you feel dizzy or nauseous. A hot flash typically lasts about three to six minutes, although the sensation can last longer and may disrupt sleep when it occurs at night.
- Irregular menstrual cycles
- Breast tenderness
- Exacerbation of migraines
- Mood swings