My father was diagnosed with polymyalgia rheumatica. what does this mean?

Inflamation muscle: Autoimmune disorder of muscles leading to diffuse muscle pain. It is usually identified by abnormal blood tests indicating inflammation such as increased CRP sed rate, and is usually treated with oral steroids like Prednisone it usually responds quickly to higher doses which are then tapered down to the lowest effective dose. The disease may come and go.