Atresia is a medical condition where a body passage or opening is absent or closed. This can occur in various parts of the body, such as the esophagus, anus, or vagina. Atresia can lead to serious health issues, as it may prevent normal bodily functions, such as eating or elimination. The condition is often present at birth and is classified as a congenital disorder. Treatment typically involves surgery to create or restore the passage, allowing for normal function. Early diagnosis and intervention are crucial for improving outcomes for individuals with atresia.