Your doctor usually can diagnose diabetic neuropathy based on your:
When necessary, more specialized testing may be done, such as:
Nerve conduction studies check whether nerve impulses in the arms and legs are normal. Electromyography tests to see how well arm and leg muscles move in response to nerve signals.
These two tests usually are done together. They involve a series of momentary minor electric shocks through small needles or pads on the skin.
Ultrasound of the bladder performed right after you have passed urine is used to see if your bladder is functioning properly. Normally there should be very little urine in the bladder after using the bathroom.
Gastric (stomach) emptying study tests how quickly food moves through your stomach. In this test, you eat food that contains a small amount of radioactive material. A series of pictures is taken by a machine that detects the radioactive signal. The inability to empty your stomach because damaged nerves can't tell the muscles to contract is called gastroparesis.
Your doctor may also want to do endoscopy to make sure nothing else is causing the gastroparesis. In endoscopy, the doctor threads a flexible tube with a camera on the end through your mouth and advances it to look inside the stomach.
Nerve biopsy involves taking a small sample of a nerve to be examined in a laboratory. This is rarely needed.