A nerve conduction study, sometimes called nerve conduction velocity, is a test to see how well nerves function. It measures the flow of electricity through a nerve and can tell if that nerve has been damaged.
Nerves use electrical signals to carry messages to the muscles and brain. During a nerve conduction study, three small electrodes are applied to the skin. One releases a very tiny electric charge, and the other two record how long the electricity takes to reach them. If a nerve has been damaged by injury or disease, electrical signals may flow through the nerve slowly or not at all.
Nerve conduction studies can sometimes be a bit uncomfortable. The test can feel a bit like being zapped with static electricity. However, it is rarely painful.
A test very similar to the nerve conduction study is electromyography, or EMG. An EMG measures electrical activity in the muscles. Quite often, a nerve conduction study and EMG are done at the same time. If a patient is experiencing weakness, pain, or numbness, these tests can help doctors diagnose the underlying problem.