更年期是女性生命中一个自然的现象。妇女到了四十五至五十五岁之间，卵巢开始缺乏足够卵胞来接受脑下垂体分泌的刺激，以致周期性的雌雄激素及孕激素越来越少，影响子宫内膜周期性的增厚、剥落及出血。结果月经周期变得不规则，时早时迟，经量时多时少。一般而言这些情况会持续一段时期，直至月经不来。当妇女超过一年以上没有月经，才可说是绝经。

香港医院管理局在2009年所进行的一项研究表示，妇女更年期的情绪症状可以维持到60岁甚至更后，年长妇女由更年期开始出现脾气暴躁将会正常化。

Menopause, also known as the climacteric, is the time in most women's lives when menstrual periods stop permanently, and they are no longer able to have children. Menopause typically occurs between 45 and 55 years of age. Medical professionals often define menopause as having occurred when a woman has not had any vaginal bleeding for a year. It may also be defined by a decrease in hormone production by the ovaries. In those who have had surgery to remove their uterus but they still have ovaries, menopause may be viewed to have occurred at the time of the surgery or when their hormone levels fell. Following the removal of the uterus, symptoms typically occur earlier, at an average of 45 years of age.