Understanding menopause and its symptoms
Menopause is defined as the cessation of menstruation for at least one year. Physiologically, it corresponds to the discontinuance of ovarian activity and therefore the end of menstrual cycles.
Female sex hormones - estrogen and progesterone - decrease.
Unlike men, who produce sperm all their lives, women have a limited stock of follicles at birth. Follicles are small sacs in the ovaries that each contain an immature egg.
At the beginning of each cycle, several follicles grow until one of them is eluted and expels a mature egg, beginning the process of ovulation which occurs in the middle of the monthly cycle.
Each woman builds up her stock of follicles before she's born. This reserve diminishes throughout her life until the reserve is completely exhausted. This is menopause.
Female follicles produce sex hormones. During the first half of the cycle, the follicle produces mostly estrogen, while the corpus luteum produces progesterone in the second half of the cycle.
As the supply of follicles diminishes, the number of sex hormones also decreases. However, the decrease in progesterone happens quicker than that of estrogen, leading to a period of excess estrogen levels which is the cause of the classic symptoms of pre-menopause, including hot flashes, vaginal dryness, mood disorders, and insomnia.