Muscular dystrophy is a group of diseases that result in the weakening of the muscles over time. In muscular dystrophy, unhealthy genes interfere with the production of proteins called dystrophy. This insufficiency of proteins, necessary for normal muscle function, makes it tough for the muscles to work normally. The absence of this protein makes coordination among muscles a difficult job.

Muscular dystrophy can occur at any age, but commonly, some forms are diagnosable in infancy or childhood. Other types may appear until middle age or later in life. Young boys are more likely to have this disease than girls, though the signs differ based on which muscles are affected.

All forms of muscular dystrophy grow intense as the muscles lose their strength.