A systematic review included 12 studies that assessed the precision and accuracy of history taking and physical examination in diagnosing CTS in adults. In patients presenting with hand dysesthesias, the findings that best distinguish between patients with electrodiagnostic evidence of CTS and patients without it were hypalgesia in the median nerve territory (LR 3.1, 95% CI 2.0-5.1), classic or probable Katz hand diagram results (LR 2.4, 95% CI 1.6-3.5), and weak thumb abduction strength (LR 1.8, 95% CI 1.4-2.3). Findings that argue against the diagnosis of carpal tunnel syndrome were unlikely Katz hand diagram results (LR 0.2, 95% CI, 0.0-0.7) and normal thumb abduction strength (LR 0.5, 95% CI, 0.4-0.7). Several traditional findings of CTS have little or no diagnostic value, including nocturnal paresthesias; Phalen and Tinel signs; thenar atrophy; and 2-point, vibratory, and monofilament sensory testing. Other less commonly used maneuvers, including the square wrist sign, flick sign, and closed fist sign, require validation by other studies before they can be recommended.