causes of stenosis
The most common cause of spinal stenosis is aging. Degenerative processes occur throughout the body as it ages. Tissues in the spine may start to thicken, and bones may get bigger, compressing the nerves. Conditions like osteoarthritis and rheumatoid arthritis may also contribute to spinal stenosis.
Causes of mitral valve stenosis include: Rheumatic fever. A complication of strep throat, rheumatic fever can damage the mitral valve. Rheumatic fever is the most common cause of mitral valve stenosis. It can damage the mitral valve by causing the flaps to thicken or fuse. Signs and symptoms of mitral valve stenosis might not show up for years.
In adults, three conditions are known to cause aortic stenosis. 1  Progressive wear and tear of a bicuspid valve present since birth (congenital).  Wear and tear of the aortic valve in the elderly.