Menopause occurs when the ovaries cease to ovulate (release eggs) and stop making estrogen (the female hormone that controls the menstrual cycle). The average age of menopause is about 50 years old, but it can occur earlier or later. Most menopausal women will benefit from hormone replacement therapy, which can stop or decrease hot flushes, improve sleep, preserve bone strength and decrease the risks of heart disease. Patients differ in their needs for hormone replacement. Treatment is individualized and periodic monitoring is necessary to evaluate side effects and prevent complications.