What chronic condition causes tenderness and fatigue in muscles?

Fibromyalgia is a chronic condition characterized by widespread musculoskeletal pain, tenderness, and fatigue. It affects how the brain processes pain signals, leading to an increased sensitivity to pain and associated symptoms such as fatigue, sleep disturbances, and cognitive issues. People with fibromyalgia often experience tender points in specific areas of the body and may have symptoms that can be exacerbated by stress, weather changes, or physical activity.

This condition differs from others listed, as osteoarthritis primarily involves joint degeneration and may not cause generalized muscle tenderness or fatigue. Rheumatoid arthritis is an autoimmune disorder that primarily affects joint inflammation and function rather than producing widespread muscle symptoms. Carpal tunnel syndrome, while causing discomfort and pain in the wrist and hand, is not a chronic condition that involves tenderness and fatigue in various muscle groups. Thus, fibromyalgia uniquely addresses the traits of tenderness and fatigue in muscles among the options given.