Polymyalgia rheumatica (PMR) is an inflammatory disorder involving pain and stiffness in the shoulder and usually also the hip.
Causes, incidence, and risk factors
Polymyalgia rheumatica is a disorder that almost always occurs in people over 50 years old. The cause is unknown.
PMR may occur alone, or with or before giant cell arteritis (also called
temporal arteritis), which is inflammation of blood vessels (usually in the head).