Muscular dystrophy is a group of conditions characterized by decreasing muscle mass and progressive weakness. This is caused by gene mutations which lead to abnormal protein production involved in forming muscles. The most common type is Duchenne muscular dystrophy (DMD); its symptoms include muscle pain, stiffness, large calf muscles, frequent falls, learning disabilities, and difficulties in moving, especially running, jumping, and rising from a lying or sitting position. There is no cure but medications and physiotherapy may help address the symptoms.