What is menopause?
Menopause refers to the time in a woman's life when she stops having a menstrual period and is no longer fertile. The time leading up to menopause is called the menopausal transition, or perimenopause.
During perimenopause, a woman's ovaries start to produce less estrogen and progesterone. Changes in these hormones cause symptoms of menopause. Periods occur less often and eventually stop. Although this typically is a gradual process that happens over time, in some cases, a woman's periods will stop suddenly. Throughout perimenopause, ovulation—the release of eggs from the ovaries—also occurs less and less frequently.1
Menopause is the point at which a woman has not had a period in 12 consecutive months. The time after menopause is called postmenopause, a phase that lasts for the rest of a woman’s life.
All women experience menopause, usually between ages 45 and 55.2 The average age of menopause is 51, but it occurs earlier in some women. Women who smoke may go through menopause earlier than women who don't smoke.3
However, perimenopause can begin several years earlier when levels of estrogen and progesterone first begin to fluctuate.2 Surgical or medical menopause is the term for a decrease in estrogen that is a result of surgery to remove the ovaries or uterus, or medical treatments such as chemotherapy or hormone therapy to treat breast cancer.2
- O’Connor, K. A., Ferrell, R., Brindle, E., Trumble, B., Shofer, J., Holman, D. J., et al. (2009). Progesterone and ovulation across stages of the transition to menopause. Menopause, 16, 1178–1187. Retrieved May 1, 2013, from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2783957/
- MedlinePlus. (2011). Menopause. Retrieved June 13, 2012, from http://www.nlm.nih.gov/medlineplus/ency/article/000894.htm
- Fleming, L. E., Levis S., LeBlanc, W. G., Dietz, N. A., Arheart, K. L., Wilkinson, J. D., et al. (2008). Earlier age at menopause, work, and tobacco smoke exposure. Menopause, 15, 1103–1108. Retrieved June 13, 2012, from http://www.ncbi.nlm.nih.gov/pubmed/18626414