Hormones are chemicals that control when and how certain organs work. They are made by glands in the body. In women, the hormone estrogen plays a key role in the reproductive system. Changes in the level of estrogen lead to menstrual periods each month. Estrogen also affects a woman’s bones and the health of her heart and blood vessels. At menopause, a woman’s body makes less estrogen and she stops having menstrual periods. This is a natural stage in a woman’s life. The lack of estrogen can bring on symptoms such as hot flushes and vaginal dryness. It can also increase the risk of heart disease and osteoporosis. Because of this, many women take hormone replacement therapy to restore estrogen after menopause. Talk with your healthcare provider about your individual hormone needs and what is best for you.