If signs and symptoms that you think might be due to carpal tunnel syndrome interfere with your normal activities — including sleep — and they persist, see your doctor. If you leave the condition untreated, nerve and muscle damage can occur.

Your doctor will most likely want to review your signs and symptoms to find out where they're located. One diagnostic key is that the median nerve doesn't provide sensation to your little fingers. Another clue is the timing of the symptoms. Typical times when you might experience symptoms due to carpal tunnel syndrome include while holding a phone or a newspaper, gripping a steering wheel, or sleeping. Your doctor will also want to test the feeling in your fingers and the strength of the muscles in your hand, because these can be affected by carpal tunnel syndrome. Pressure on the median nerve at the wrist, produced by either bending the wrist, tapping on the nerve or simply pressing on the nerve, can bring on the symptoms in many people.

If you have signs and symptoms of carpal tunnel syndrome, your doctor may recommend the following diagnostic tests:

• Electromyogram. Electromyography measures the tiny electrical discharges produced in muscles. A thin-needle electrode is inserted into the muscles your doctor wants to study. An instrument records the electrical activity in your muscle at rest and as you contract the muscle. This test can help determine if muscle damage has occurred.

• Nerve conduction study. In a variation of electromyography, two electrodes are taped to your skin. A small shock is passed through the median nerve to see if electrical impulses are slowed in the carpal tunnel.

These tests are also useful in checking for other conditions that might mimic carpal tunnel syndrome, such as a pinched nerve in your neck. Your doctor may recommend that you see a rheumatologist, neurologist, hand surgeon or neurosurgeon — depending on whether you have additional signs or symptoms of other medical disorders or need specialized treatment.