Aortic valve stenosis — or aortic stenosis — occurs when the heart's aortic valve narrows. This narrowing prevents the valve from opening fully, which obstructs blood flow from your heart into your aorta and onward to the rest of your body.
When the aortic valve is obstructed, your heart needs to work harder to pump blood to your body. Eventually, this extra work limits the amount of blood it can pump and may weaken your heart muscle.
If you have severe aortic valve stenosis, you'll usually need surgery to replace the valve. Left untreated, aortic valve stenosis can lead to serious heart problems.