A complete hydatidiform mole is a type of abnormal pregnancy that occurs when an egg with no genetic material is fertilized by a sperm, leading to the growth of abnormal tissue instead of a viable fetus. This condition results in the formation of cysts that resemble grape-like clusters, which can fill the uterus. Women with a complete hydatidiform mole may experience symptoms such as vaginal bleeding, rapid uterine growth, and elevated levels of the hormone human chorionic gonadotropin (hCG). Diagnosis is typically made through ultrasound and blood tests, and treatment often involves the removal of the molar tissue to prevent complications.