Doctors generally perform physical exams, X-rays, nerve conduction tests and electromyograms to diagnose carpal tunnel, according to Mayo Clinic. Doctors also consider the history and timing of symptoms to rule out other conditions.
The physical exam may include the Tinel's sign test and the Phalen's sign test to check for tingling, numbness or pain in the hands and fingers, reports WebMD. When symptoms do not respond to treatments, doctors may order additional tests such as ultrasounds or MRIs to look for swelling or other abnormalities. Sometimes, doctors use blood tests to look for other medical problems, such as arthritis or thyroid issues, that may be causing the symptoms.