Joint inflammation has been demonstrated in some cases, which supports the contention that polymyalgia rheumatica is a form of synovitis of the proximal joints and periarticular structures. Marked tenosynovitis may cause diffuse distal extremity swelling with pitting edema. Upon careful testing, muscle strength is found to be normal or nearly normal. Normochromic anemia is typical. Other acute-phase protein levels are also elevated.
Some patients have mild hepatic dysfunction that reverts to normal with treatment.
Other tests are normal. White individuals appear to be affected more frequently than other groups. The highest recorded incidence rates are from northern Europe and the northern United States. In one population study, the prevalence found was approximately 1 in 200 persons in the population aged 50 or older. Recent reports on incidence rates in Europe show similar findings.