Atresia refers to a medical condition characterized by the complete closure or absence of a natural body opening or passage. Some synonyms for this word include obstruction, blockage, closure, occlusion, and constriction. These terms all describe a condition in which fluid, air, or other materials are prevented from passing through their normal pathways. Atresia can occur in various parts of the body, such as the digestive system, urinary tract, or respiratory system. Treatment for atresia may involve surgical intervention to open the affected passage or create a new opening. Early diagnosis and intervention are crucial for better prognosis and long-term outcomes for individuals with atresia.