What should you know about an OTC TENS unit?

TENS uses adhesive electrodes connected to a small battery-powered device. The sensation is usually tingling or tapping rather than a painful shock, and intensity should remain comfortable. It may change how pain signals are experienced while the device is running, but response differs between people and conditions.

TENS is not a substitute for assessment when pain is new, progressive, or associated with weakness, altered sensation, or injury. It should not be placed over irritated or broken skin, the front of the neck, or areas where sensation is reduced.

Read the device instructions, inspect the electrode pads, and start at a low setting. Place pads on clean, dry skin around—not directly over—the painful area as directed. Turn the unit off before moving pads, and stop for skin irritation, burning, dizziness, palpitations, or increased pain. Keep the device away from water and do not sleep with it unless a clinician specifically advises this.

Ask a clinician before use if you have a pacemaker, implanted electrical device, seizure disorder, pregnancy-related concerns, or uncertain skin sensation. A physiotherapist can help position electrodes and pair TENS with exercises that address the cause.

Get urgent help for chest pain, fainting, breathing difficulty, new severe weakness, loss of bladder or bowel control, or pain after major trauma. Stop using TENS and seek advice for a significant skin reaction or new neurological symptoms.

Ask whether TENS suits your diagnosis, where pads should go, which settings are reasonable, and how to combine it with movement or physiotherapy. Confirm whether any implanted device or skin condition makes it unsuitable.