Menopause occurs because the ovaries progressively exhaust their finite supply of follicles. Women are born with approximately one to two million eggs, a number that declines throughout life and falls sharply in the years leading up to the final menstrual period, typically between ages 45 and 55.
As follicle numbers drop, the ovaries produce less estradiol and progesterone. The brain's hypothalamus and pituitary respond by releasing higher levels of FSH and LH, yet the ovaries can no longer respond predictably. According to The Menopause Society, this hormonal recalibration drives vasomotor symptoms, urogenital changes, and sleep disturbance.
Estrogen also regulates temperature control, bone density, vaginal tissue health, cognitive processing, and mood stability. As levels fall, these systems lose a key signaling molecule, which is why targeted interventions like Hormone Replacement Therapy (BHRT) can restore balance across multiple symptom domains at once.
