Definition of Polymyalgia rheumatica:

Polymyalgia rheumatica is an inflammatory disorder involving pain and stiffness in the hip or shoulder area.

Causes, incidence, and risk factors:

Polymyalgia rheumatica is a disorder that almost always occurs in persons over 50 years old. The cause is unknown. Although symptoms are located predominantly in the muscles and there are no outward signs of arthritis, in some cases there is evidence of inflammatory arthritis.

The disorder may occur independently, or it may coexist with or precede temporal arteritis, which is an inflammation of blood vessels (usually in the head).