Menopause (also known as the "Change of life" or climacteric) is a stage of the human female reproductive cycle that occurs as the ovaries stop producing estrogen, causing the reproductive system to gradually shut down. As the body adapts to the changing levels of natural hormones, vasomotor symptoms such as hot flashes and palpitations, psychological symptoms such as increased depression, anxiety, irritability, mood swings and lack of concentration, and atrophic symptoms such as vaginal dryness and urgency of urination appear. Together with these symptoms, the woman may also have increasingly scanty and erratic menstrual periods.

Technically, menopause refers to the ceasing of menses; whereas the gradual process through which this occurs, which typically takes a year but may last as little as six months or more than five years, is known as climacteric. Popular use, however, replaces climacteric with menopause. Menopause can either be natural or surgically induced. A natural or physiological menopause refers to the ceasing of menses that is a part of a woman's normal ageing process. However, a surgically induced menopause refers to the ceasing of menses for reasons such as because the woman has had a previous hysterectomy.

The average onset of menopause is 50.5 years, but some women enter menopause at a younger age, especially if they have suffered from cancer or another serious illness and undergone chemotherapy. Premature menopause (or Premature Ovarian Failure) is defined as menopause occurring before the age of 40, and occurs in 1% of women. Other causes of premature menopause include autoimmune disorders like thyroid disease or diabetes mellitus. Premature menopause is diagnosed by measuring the levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH); the levels of these hormones will be higher if menopause has occurred. Rates of premature menopause have been found to be significantly higher in both fraternal and identical twins; approximately 5% of twins reach menopause before the age of 40. The reasons for this are not completely understood. Cases of transplant of ovarian tissue between identical twins have been successful in restoring fertility.

Post-menopausal women, especially Europeans, are at increased risk of osteoporosis.

Menopause is rare in animal species. One possible explanation for its evolution in humans is the grandmother hypothesis.

Treatment of symptoms

Medical treatments for menopausal symptoms have been developed. Most notably, Hormone Replacement Therapy (HRT), has been used to reduce the weakening of bones (known as osteoporosis) and the risk of heart disease after menopause. However, some women have resisted the implication that menopause is a disorder, seeing it as a natural stage of life. There has also been scientific controversy over whether the benefits of HRT outweigh the risks. Specifically, recent studies have suggested that HRT may increase women's risk for Alzheimer's disease, breast cancer, heart disease and stroke.

See also: teriparatide, andropause (a similar process in men).

External links

• http://www.YourMenopause.com
• http://www.homoeopathyclinic.com/articles/Menopause.pdf
• http://www.bwcpc.com/Pages/Menopause.htm
• Menopause Fact Sheet
• Menopause UK with alternatives to HRT
• Isoflavones and menopause symptoms
• eMedicine Health: Menopause
• Menopause Expert
• Articles on Menopause, Black Cohosh and HRT
• Ovarian transplantation between monozygotic twins discordant for premature ovarian failurede:Menopause

es:Menopausia fr:Ménopause he:גיל הבלות lt:Menopauzė nl:Menopauze sv:Klimakterium zh:更年期