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cambtone eNotes educator| Certified Educator

Atrophy means wasting away, and can refer to both tissues and organs.  It may be caused by a number of factors, such as lack of use or by restriction of blood supply.  In the case of the arm, it could also be caused by bone disease such as rheumatoid arthritis or oestoarthritis which can lead to impaired movement and muscle wastage (atrophy, or reduction in muscle mass).  Trauma can also have a similar effect, either impairing movement (e.g. setting the arm in a cast) or by damage to the vascular and/or nerve supplies to the arm.  Atrophy may also be a result of some diseases which reduce the supply of blood, and therefore oxygen, to the arm. These are often autoimmune diseases where the bllod vessles themselves are attcked by the body's immune system.