Abstract
Hematocolpos, characterized by the accumulation of menstrual blood in the vagina, is a rare condition often misdiagnosed due to its uncommon occurrence and non-specific symptoms. Main causes include imperforate hymen, obstructed hemivagina with ipsilateral renal anomaly (OHVIRA), congenital lower vaginal atresia, and complete transverse vaginal septum. Without early diagnosis and treatment, complications such as tubal adhesion, pelvic endometriosis, and infertility can occur. This article reviews the differential diagnosis and treatment of hematocolpos.