Severity of carpal tunnel syndrome (CTS) can be difficult to assess before surgery. Sometimes patients have minor symptoms with severe nerve compression. Other times patients report severe symptoms with minor compression.

Tests used by doctors to make the diagnosis include Phalen's test, Tinel's sign, carpal-compression test, and several others. Only Phalen's test (prolonged wrist flexion) can link the severity of the condition with the symptoms.

Studies show that the results of nerve conduction tests before surgery may be a good way to tell the final outcome. Evidently certain values can forecast or predict improvement in symptoms and functional use of the hand. If you haven't had these tests done, you may want to ask the surgeon about them.