A woman's reproductive and sexual health has a distinct difference compared to men's health. Even in developed countries pregnancy and childbirth are associated with substantial risks. Postmenopausal women are at higher risk of heart disease and osteoporosis, presumably because of a decrease in the production of estrogen or other hormones. Several unpleasant symptoms may accompany menopause. Some, such as vaginal dryness, result from the lack of estrogen. Others, such as hot flashes and decreased sex drive, are caused by more complex hormonal changes. Some women experience depression, anxiety, or insomnia during menopause.