1. Working
- Electrode Pads: TENS devices consist of electrode pads that are placed on the skin over the painful area.
- Electrical Pulses: These pads deliver controlled, mild electrical pulses to the nerves beneath the skin's surface.
- Nerve Stimulation: The electrical pulses stimulate sensory nerves, which can lead to the release of endorphins, the body's natural painkillers.

2. Pain Relief Mechanism
- Gate Control Theory: TENS may work by "closing the gate" on pain signals, meaning it interferes with pain transmission in the spinal cord.
- Endorphin Release: TENS can trigger the release of endorphins, reducing pain perception and providing a sense of well-being.

3. Types of TENS
- Conventional TENS: Delivers high-frequency, low-intensity pulses for short-term pain relief.
- Acupuncture-like TENS: Uses low-frequency, high-intensity pulses, mimicking acupuncture's effects.
- Burst Mode TENS: Provides bursts of high-frequency pulses, often used for chronic pain.

4. Uses
- TENS is commonly used to manage various types of pain, including musculoskeletal pain, neuropathic pain, and labor pain.
- It's a non-pharmacological option, making it attractive for those seeking alternatives to pain medications.

5. Considerations
- TENS should be used under the guidance of a healthcare professional.
- Individual response to TENS can vary, and it may not work for everyone.
- Proper electrode pad placement and device settings are crucial for effectiveness.