M60-M63: Disorders of muscles

M60: Myositis

Myositis refers to a group of conditions that cause inflammation within the muscles. This inflammation can be originated from various causes, including auto-immune diseases, infections, medications, or injury. Although the major symptom is muscle weakness, it can also present as muscle pain, fatigue, difficulty swallowing and breathing, as well as skin rashes in some types of myositis. The course of disease progression is variable and can be acutely sudden or progressively chronic. The conditions primarily affect skeletal muscles, which are the muscles involved in movement. However, when severe, myositis can affect other body systems, leading to issues such as difficulty breathing and swallowing.