In children with certain throat infections, proper antibiotic treatment can prevent this condition. Other causes are not usually preventable.
Long-term effects depend on the tightness of the valve. A person with mild mitral stenosis may have no long-term effects. A person with severe mitral stenosis may have serious heart and lung complications, including irregular heartbeats, blood clots, and permanent heart damage.
Mitral stenosis is not contagious and poses no risk to others. However, the infection that causes rheumatic fever, the most common cause of mitral stenosis, is contagious.