What is menopause?

Confusingly, there are several stages of menopausal transition. Here are some definitions:

•  Peri-menopause: The period when a woman’s supply of eggs is running out and her hormone levels (of oestrogen, progesterone and testosterone) are decreasing. This transition time to the end of a woman’s reproductive life can last 4 to 10 years and causes unpredictable fluctuations in hormone levels, which may result in debilitating symptoms. This is the phase which, in general society, is commonly, but inaccurately, referred to as ‘menopause’.
  
• Menopause: This is actually one date in time, when a woman has her final menstrual period after her last egg has been released. Natural menopause is only confirmed retrospectively, after a woman has experienced 12 months of having no periods (amenorrhoea). Menopause usually occurs between the ages of 45 to 55, with the average age being 51. 
  
• Post-menopause: Begins from 12 months after a woman’s final menstrual period. 
• Premature menopause: Menopause which occurs at ages less than 40 years. 
• Surgical or chemical menopause: After ovaries are surgically removed or, for example, as a result of chemotherapy or other types of cancer treatment in some women.