Transcutaneous electric nerve stimulation (TENS) is a non-invasive method of pain relief using electric stimulation of sensory nerves. There are different types of TENS including conventional/high frequency TENS, acupuncture/low frequency TENS, burst TENS, and brief/intense TENS, each with different parameters and mechanisms of pain relief. TENS is commonly used to relieve acute pain after surgery or childbirth as well as chronic pain from conditions like low back pain, arthritis, and myofascial pain by applying electrical stimulation to sites over painful areas, dermatomes, or acupuncture points. Contraindications for TENS use include pacemakers, untreated pain conditions, and certain cardiac or neurological conditions.