Menopause refers to the end of the menstrual cycle. This usually occurs in women aged 45 -55 years. If women less than 45 years of age undergo menopause, it is called early menopause.
When the production of eggs by the ovaries stops, there is a fall in the hormone estrogen. This estrogen is responsible for the female reproductive cycle. A fall in estrogen leads to menopause. Additionally, when the ovaries are removed (for other medical conditions like cancer) it can lead to menopause.