What should you know about a muscle TENS unit?

TENS stands for transcutaneous electrical nerve stimulation. Sticky pads sit on the skin near, but not directly over, the painful area. The device sends a mild pulsing current that can change how pain signals are processed. It does not repair a torn muscle or remove the underlying cause of pain. You may feel tingling, tapping, or a rhythmic pulsing; the setting should remain comfortable rather than sharp or painful.

TENS can be useful alongside a broader plan for a strain, joint problem, or rehabilitation programme. Its effect varies, and relief may last only while the device is running or for a short time afterwards.

Follow the device instructions and any advice from your clinician. Place electrodes on clean, intact skin, keep the unit switched off while attaching or removing pads, and begin with a low intensity. Check the skin after use for persistent redness, blistering, or irritation. Do not place pads across the front of the neck, over the head, across the chest, or over broken or infected skin. Avoid using a TENS unit while driving, bathing, swimming, or sleeping unless a qualified clinician has specifically advised it.

Ask for professional guidance before use if you have a pacemaker or other implanted electrical device, reduced sensation, epilepsy, or are pregnant. A physiotherapist can help position pads and combine TENS with exercises. See the related guide on [TENS Unit](/technology/tens-unit/).

Stop the device and seek medical advice if it causes a burn, severe skin reaction, worsening pain, dizziness, unusual weakness, or a new change in sensation. Arrange an assessment when pain follows a significant injury, prevents normal use of the limb, or is not improving. Sudden severe pain with marked swelling, deformity, chest discomfort, or trouble breathing needs urgent care.

Ask which body area and pad position are appropriate, how long each session should last, and whether TENS fits your diagnosis and medicines. Also ask what symptoms mean you should stop and whether supervised rehabilitation would address the cause of the pain.