Could a sed rate over 100 concern for cancer if blood counts are normal? symptoms is terrible muscle aches, stiffness, and some muscle weakness 79 y/o man.

Autoimmune: My concern would be for an autoimmune disease vs. Infectious, discuss with your primary care for further workup - the differential is pretty broad at this point.

Less likely: High sed rates indicate inflammation. The complaints of muscle aches and weakness and stiffness suggests poymyositis. Futher evaluation by a rheumatologist with muscle enzyme tests and possible muscle biopsy may be necessary. If proven a trial of steroid therapy would be helpful. Pulmonary involvement with interstitial lung disease can occur.