The essential symptoms of fibrositis--widespread aching and pain, disturbed sleep, morning stiffness, and fatigue--are common in both rheumatic and nonrheumatic patients. But the essential sign of fibrositis--widespread local tenderness over specific anatomic sites ("tender points")--is rare in any patients except those with fibrositis. Clinical criteria for the diagnosis of fibrositis rely heavily on a high tender point count in the presence of characteristic fibrositic symptoms. Multiple tender points are uncommon in normal subjects and in those with rheumatic and nonrheumatic disorders. The tender point count thus also serves to distinguish fibrositis from other musculoskeletal diseases.