Ever wondered why menopause actually happens? There are reasons for our menstrual cycles ending at a certain point, and it has a lot to do with our hormones. How do our hormones change our menstrual cycles and stimulate menopause to start, and why? To learn more about why menopause happens, keep reading this blog post!
Why Does Menopause Happen: How menstrual cycles occur
Our brain is involved in controlling our menstrual cycle. A part of the brain called the hypothalamus communicates to the pituitary gland to release chemicals that trigger our ovaries to release progesterone and estrogen. It is through these chemical signals and the fluctuating levels of our sex hormones that the menstrual cycle occurs.
There are four stages to the menstrual cycle, the menstrual phase, the follicular phase, the ovulation phase and the luteal phase. During the menstrual phase, our uterus lining is shedding as there is no fertilised egg present. This is when you have your period. During the follicular phase, the hypothalamus stimulates the pituitary gland to release a hormone called follicle stimulating hormone (FSH).
FSH prompts the ovaries to produce around 5-10 sacs called follicles, each of which contain an immature egg. As the eggs mature, the healthiest is chosen to travel down the fallopian tube.
The release of the mature egg occurs during the ovulation phase. During the luteal phase of the menstrual cycle, the follicle turns into another structure, called the corpus luteum. The corpus luteum releases both estrogen and progesterone that help to thicken the lining of the uterus in preparation for a fertilised egg.
Why Does Menopause Happen: Number of eggs & age
When menopause happens to a person due to aging, it is because the ovaries no longer produce or release sex hormones and they no longer produce or release eggs. With no sex hormones and no eggs, menstruation cannot occur.
As a woman ages, the number of eggs that she has declines. It is thought that at birth, a woman has approximately 1-3 million eggs. By the time of menopause, a woman may have around 10,000 eggs or less. Some of the eggs die off, while the remaining ones become more resistant to FSH, as menopause approaches.
Why Does Menopause Happen: Hormone levels
Along with the number of eggs that the ovaries produce declining, the hormone production declines also. Estrogen is required for the menstrual cycle to occur, but as menopause approaches, estrogen levels drop until the ovaries no longer produce it.
After menopause, the body still produces estrogen, it is just not produced by the ovaries. Instead, the adrenal glands produce androgens that can be converted into estrogen.
Why Does Menopause Happen: Other causes of menopause
Menopause is not only caused by age. There are a number of other reasons why menopause may happen earlier in life. These include the development of autoimmune diseases, family history of early menopause, smoking, chemotherapy, radiation, surgical menopause or infections. We have a great article on the causes of menopause other than age on our website. If you are interested, definitely check it out.