I heard there's a simple blood test that can show what is causing my carpal tunnel syndrome. What is this test called?

Carpal tunnel syndrome (CTS) has many possible causes. Only a few can be identified by a blood test. Diabetes can be a cause of numbness and tingling in the fingers.

This is called diabetic neuropathy but often gets labeled as CTS. A fasting blood glucose test shows the presence of the diabetes, which helps pinpoint the cause of the symptoms.

Low thyroid hormone causing hypothyroidism can also result in CTS. Once again a blood test showing the levels of thyroid help identify the cause of the symptoms.

Other medical conditions causing symptoms similar to CTS that can be identified with a blood test include pernicious anemia, leukemia, and vitamin deficiency.

Soft tissue causes cannot be identified with a blood test. But there are other tests the physician can perform to pinpoint the diagnosis. During the physical exam, special tests of the median nerve involved in CTS can be performed.

If necessary, electromyography (EMG) studies can be done to test the nerve conduction. Less invasive testing may include X-rays, ultrasound studies, and MRIs.