Menopause is a hallmark in the reproductive life of every woman, and simply indicates the natural and permanent cessation of fertility and the menstrual cycle. However, the physical and emotional components of menopause are more complex. When a female is born, she has one to two million egg-containing follicles in her ovaries. These represent all of the eggs she'll ever have. From the onset of puberty in her teenage years, she will begin her monthly menstrual cycles. This means that her body will release an egg into one of her fallopian tubes every month. If the egg remains unfertilized by a man's sperm, a woman's body will expel it as part of her monthly period. This cycle continues every month for much of a woman's life. Over time, however, her finite supply of egg follicles will diminish, both from years of ovulation and from a natural degenerative process. As the follicle supply is depleted, her ovaries gradually stop making estrogen and progesterone, the hormones that have regulated her menstrual cycle throughout her life. Physically, this will result in cessation of monthly menstrual periods. In fact, the definition of menopause is when a woman has gone twelve consecutive months without menstruating. Many other physical symptoms can follow this depletion, including hot flashes, decreased libido, insomnia, and night sweats. Menopause is a major milestone, and most women also experience emotional symptoms, like mood swings, irritability, and even depression, which are exacerbated by hormonal fluctuations. Menopause is actually preceded by a time referred to as perimenopause, which typically begins in a woman's forties. During this transitional period, the ovaries gradually decrease estrogen production, thereby lowering fertility and often causing irregular cycles. The average length of perimenopause is approximately four years, but is highly variable both in terms of onset and duration. Irregular periods and decreased fertility are signs that perimenopause has begun, although many women do not notice any symptoms at all unless they are attempting to conceive. Menopause typically occurs between the ages of 50 and 52, but some women experience loss of ovarian function before the age of 40. This is called premature menopause. There are various causes for premature menopause. A common one is oophorectomy, which is surgical removal of the ovaries. Some women experience a condition called premature ovarian failure, which is a genetic condition in which the ovaries simply stop working too soon. In addition, cancer chemotherapy and pelvic radiation treatments may lead to premature menopause. Regardless of when it occurs, menopause can be a challenging time, both physically and emotionally. For this reason, it's important for a woman to build a network of supportive individuals that she can talk to. Menopause is a natural stage in a woman's life, and it is nothing to be frightened or embarrassed about. If you have concerns about menopause, please make an appointment to discuss them with your doctor.