ImportanceCarpal tunnel syndrome, trigger finger, de Quervain tenosynovitis, and basilar (carpometacarpal) joint arthritis of the thumb can be associated with significant disability.ObservationsCarpal tunnel syndrome is characterized by numbness and tingling in the thumb and the index, middle, and radial ring fingers and by weakness of thumb opposition when severe. It is more common in women and people who are obese, have diabetes, and work in occupations involving use of keyboards, computer mouse, heavy machinery, or vibrating manual tools. The Durkan physical examination maneuver, consisting of firm digital pressure across the carpal tunnel to reproduce symptoms, is 64% sensitive and 83% specific for carpal tunnel syndrome. People with suspected proximal compression or other compressive neuropathies should undergo electrodiagnostic testing, which is approximately more than 80% sensitive and 95% specific for carpal tunnel syndrome. Splinting or steroid injection may temporarily relieve symptoms. Patients who do not respond to conservative therapies may undergo open or endoscopic carpal tunnel release for definitive treatment. Trigger finger, which involves abnormal resistance to smooth flexion and extension (“triggering”) of the affected finger, affects up to 20% of adults with diabetes and approximately 2% of the general population. Steroid injection is the first-line therapy but is less efficacious in people with insulin-dependent diabetes. People with diabetes and those with recurrent symptoms may benefit from early surgical release. de Quervain tenosynovitis, consisting of swelling of the extensor tendons at the wrist, is more common in women than in men. People with frequent mobile phone use are at increased risk. The median age of onset is 40 to 59 years. Steroid injections relieve symptoms in approximately 72% of patients, particularly when combined with immobilization. People with recurrent symptoms may be considered for surgical release of the first dorsal extensor compartment. Thumb carpometacarpal joint arthritis affects approximately 33% of postmenopausal women, according to radiographic evidence of carpometacarpal arthritis. Approximately 20% of patients require treatment for pain and disability. Nonsurgical interventions (immobilization, steroid injection, and pain medication) relieve pain but do not alter disease progression. Surgery may be appropriate for patients unresponsive to conservative treatments.Conclusions and RelevanceCarpal tunnel syndrome, trigger finger, de Quervain tenosynovitis, and thumb carpometacarpal joint arthritis can be associated with significant disability. First-line treatment for each condition consists of steroid injection, immobilization, or both. For patients who do not respond to noninvasive therapy or for progressive disease despite conservative therapy, surgical treatment is safe and effective.