context: Aortic stenosis is a type of heart valve disease. Your doctor may classify it as mild, moderate, or severe. Which stage you have depends on how damaged your aortic valve is and the amount of blood that's still able to pass through it. Even so, not everyone will have the same symptoms or need the same treatments. Your aortic valve transfers blood from the left ventricle of your heart to your aorta, the largest artery you have. If something causes this valve to narrow, you can't get as much blood flow to your heart and the rest of your body. While aortic stenosis is most common in older people, some children are born with it. Aortic stenosis might not affect your health right away. In fact, many people who have a mild case may not notice any symptoms. As your aortic valve's opening slowly starts to shrink with this condition, your heart muscle picks up the slack. It can take many years for this extra work to cause severe damage to your heart muscle. The most common early warning signs are: Needing to make more effort than usual during a physical activity Feeling tired all the time A child or infant with the condition could also have chest pain after a lot of activity. Because these symptoms are so subtle, most people find out about mild cases during a checkup. When your doctor listens to your heart, she may hear an abnormal whooshing sound between heartbeats. Called a heart murmur, this distinct sound can show up long before other aortic stenosis symptoms. You can have a slightly more advanced case of aortic stenosis but still not show any symptoms. Or, you may start to feel the effects of a smaller aortic valve opening and the strain that's putting on your heart. If your condition is moderate, you may notice: Feeling out of breath, especially when you're active Chest pain Tightness or pressure in your chest Heart palpitations (rapid heartbeats) Feeling that your normal exercise has become harder Your doctor may also hear a heart murmur during an exam. Over time, your aortic valve opening may end up going from the size of a nickel to about the size of the head of a golf tee. This continues to cause more wear and tear on your heart. If your aortic stenosis is severe, you may have the same symptoms as some people with moderate cases -- such as chest pain, tightness, shortness of breath when you're active, and fainting. These signs can also mean that the disease is starting to worsen more quickly. If left untreated, severe aortic stenosis can lead to heart failure. Intense fatigue, shortness of breath, and swelling of your ankles and feet are all signs of this. It can also lead to heart rhythm problems (arrhythmias) and even sudden cardiac death. Still, some people -- especially older adults -- can have a severe case without any symptoms. The only warning you may have is a lower amount of energy when you do physical activity. If so, it might be what doctors call asymptomatic aortic stenosis. Because signs of this condition vary so widely, your doctor will want to do tests to see how well your heart is working. Your treatment will be based on your symptoms as well as what these tests show. In severe cases, surgery is likely needed to repair or replace your aortic valve. But if you're not having any symptoms, your doctor may want to off on medical treatments. Instead, he may suggest âwatchful waiting,â which means simply keeping a close eye on your heart health for now and treating any other cardiac conditions you may have.