Perimenopause is the transitional phase leading up to menopause, marking the end of a woman's reproductive years. It typically begins in a woman's 30s or 40s and can last several years. During this time, hormone levels fluctuate, leading to changes in menstrual cycles, such as irregular periods, lighter or heavier flow, and varying cycle lengths. Common symptoms of perimenopause include hot flashes, night sweats, mood swings, and sleep disturbances. These changes occur as the body gradually produces less estrogen and progesterone. Understanding perimenopause can help women prepare for this natural stage of life and manage its symptoms effectively.