Breathlessness is usually a symptom of lung disease (e.g. asthma and chronic obstructive pulmonary disease)or heart disease. These conditions often co-exist in patients with musculoskeletal disease like osteoarthritis or rheumatoid arthritis. Rheumatoid arthritis may occasionally cause myocarditis and pericarditis that will lead to breathlessness, but it is important to exclude other more common heart and lung diseases, before breathlessness is ascribed to a musculoskeletal disorder. Neuromuscular disorders like multiple sclerosis and muscular dystrophia may occasionally cause breathlessness.