IBM stands for Inclusion Body Myositis, which is a rare muscle-wasting condition that causes muscles to become thin and weak. It is one of the most common disabling inflammatory myopathies among patients older than age 50. IBM is classified along with polymyositis, dermatomyositis, and autoimmune necrotizing myopathy as one of the idiopathic inflammatory myopathies, which are a group of disorders characterized by inflammation of the skeletal muscle. The cause of IBM is unknown, but it is thought to be a form of autoimmune disorder where the bodys immune system attacks its own tissues, in this case, the muscles. The onset of muscle weakness in IBM is generally gradual and affects both proximal and distal muscles. The symptoms of IBM include progressive weakness in muscles of the hand, forearm, thigh, and lower leg, difficulty swallowing, and falling and tripping. There is no cure for IBM, and the disease is generally unresponsive to corticosteroids and immunosuppressive drugs. However, a combination of medication and rehabilitation therapy can be beneficial for many patients.