Muscle atrophy can result from lack of muscle movement and use, in which case it is called disuse atrophy. Causes include a sedentary lifestyle, being bedridden, injuries, osteoarthritis, and rheumatoid arthritis (chronic autoimmune disease characterized by joint inflammation). Another type of muscle atrophy is neurogenic atrophy, which is muscle atrophy due to a nerve problem, such as neuropathy and neuromuscular disease. Some causes of muscular atrophy can be seen as follows:

Osteoarthritis (common type of arthritis that causes pain and immobility)

Polymyositis (widespread inflammation and weakness of muscles)

Rheumatoid arthritis (chronic autoimmune disease characterized by joint inflammation)

General causes of muscle atrophy

Muscle atrophy may be caused by situations or conditions including:

Being bedridden

Dermatomyositis (a condition characterized by muscle inflammation and skin rash)

Injury, such as a broken arm or leg that must be immobilized

Malnutrition (progressive weakening and inability to adequately use muscles)

Muscular dystrophy (inherited disorder that causes a progressive loss of muscle tissue and muscle weakness)