Aortic stenosis is a heart condition where the aortic valve narrows, making it difficult for blood to flow from the heart to the rest of the body. This narrowing can lead to increased pressure in the heart and reduced blood supply, causing symptoms like chest pain, fatigue, and shortness of breath. The condition can be caused by age-related wear and tear, congenital heart defects, or rheumatic fever. Diagnosis typically involves echocardiograms and other imaging tests. Treatment options may include medication, lifestyle changes, or surgical procedures like valve replacement to improve blood flow and alleviate symptoms.