Menopause is the permanent cessation of menstruation and fertility in women caused by a lack of ovarian activity. As women transition through menopause, their bodies experience a more than 90% decrease in estrogen production which can cause symptoms like hot flashes and disrupt daily activities. After 12 months without a period, women are considered postmenopausal, which is associated with an increased risk of health issues like osteoporosis and heart disease due to aging and lower estrogen levels.