What should you know about TENS unit voltage?

Voltage describes electrical potential, but the sensation you feel also depends on pulse width, frequency, electrode contact, pad placement, and skin resistance. For that reason, a voltage value alone does not tell you whether a setting is suitable. Consumer TENS devices often present controls as intensity levels rather than a voltage value. A stronger setting is not automatically more helpful; the goal is a tolerable sensation without sharp pain, burning, or forceful muscle contraction unless a clinician has selected that response.

Apply the pads firmly to clean, dry, intact skin and connect the leads before switching the unit on. Start at the lowest setting, then increase gradually while seated. Keep the intensity steady if the tingling is comfortable. Turn the unit off before changing pad position or disconnecting a lead. Never modify the device, bypass its controls, or connect it to another power source. Follow the model-specific instructions because controls and programmes differ.

Stop if the current feels painful, causes burning, produces a persistent skin mark, or triggers dizziness, chest discomfort, or an irregular heartbeat sensation. Seek clinical advice for new weakness, worsening numbness, or pain that is not following its usual pattern. Have a professional review the unit if output changes unexpectedly or one pad feels much stronger than the other.

Ask which intensity range is reasonable for your condition, whether muscle contraction is intended, and how to respond if the sensation fades during a session.