How does a TENS unit help fibromyalgia?

Transcutaneous Electrical Nerve Stimulation (TENS) is a therapeutic modality that produces electrical stimulations to the skin and underlying tissues with the intent of causing pain relief. It consists of a generator machine with a number of ‘electrodes’ that you attach to the skin over a painful area. The theory behind it is that electrical stimulations interfere with peripheral nerve and muscle function leading to relief.

TENS is thought to be most effective over local areas. It has been most studied in local musculoskeletal pain problems, such as chronic back pain. The studies with TENS in local pain problems are not consistent, with some studies showing benefit and other not. Fibromyalgia is typically thought as a disorder of generalized pain throughout the body, making TENS an unattractive option for many fibromyalgia patients. It is not practical to perform ‘whole body’ stimulation with TENS. The most recent study of TENS in fibromyalgia observed a decrease of pain (on a scale of 0-100) of 77.5 to 62.5 (Lofgren 2009). The effects seem to be modest when it does work and it is clearly not effective for all people that try it.

Clinically, TENS has been widely used for patients with chronic pain and is very safe. It is non-invasive and can be performed at home. It is best used to treat specific pain areas. It should be avoided by people with pacemakers, epilepsy, chronic numbness, and should not be used near eye or over a certain part of the neck (carotid sinus). People who seem to successfully use the therapy typically undergo training with the machine by a trained therapist and regular follow-up with such therapists. Machines are of highly variable quality and complexity, which is often reflected in cost. It would be best to contact a physiatrist or rehabilitation specialist to discuss TENS and help with choosing the right TENS machine.