Transcutaneous Electrical Nerve Stimulation (TENS) offers a non-invasive, drug-free method for managing various types of pain, including headaches. TENS uses a small device to send mild electrical pulses through electrodes placed on the skin, targeting underlying nerves. This electrical current activates specific nerve pathways, reducing or blocking pain signals from traveling to the brain. The stimulation may also encourage the body to release natural pain-relieving chemicals called endorphins. Applying the electrodes to the correct location is essential for effective headache relief.
Preparing the TENS Unit and Skin
Before applying the electrodes, preparation ensures safety and maximum effectiveness. The skin where the electrodes will be placed must be clean, dry, and free of lotions, oils, or creams. Cleaning the area helps create a strong bond between the adhesive pad and the skin, allowing the electrical current to transmit efficiently. Poor contact can lead to concentrated current, which may feel uncomfortable or cause skin irritation.
Users must confirm the TENS unit is turned off before connecting the lead wires and applying the pads. It is important to check the lead wires for damage and ensure the batteries are adequately charged. Safety guidelines advise never placing electrodes:
- Over broken skin, open wounds, or areas that are swollen or infected.
- Directly on the front of the neck near the carotid artery.
- Over the eyes.
Targeted Placement for Tension Headaches
Tension headaches are often linked to muscle tightness in the neck, shoulders, and the back of the head. Effective TENS placement targets the muscles and nerves in the upper neck and suboccipital region. The goal is to stimulate these areas to promote relaxation and interfere with pain signals originating from the tense muscles.
Electrodes are typically placed on both sides of the upper cervical spine, just below the hairline at the base of the skull. This placement should be lateral to the second and third cervical vertebrae, which can be located by feeling for the first bony prominence moving down the neck. This stimulates the occipital nerves, which are frequently involved in tension-related pain.
If the pain extends into the shoulders, a second set of electrodes can be placed on the upper trapezius muscles. This creates a “sandwich” effect, where the current passes through the bulk of the tight muscle, promoting deep muscle relaxation. The electrodes should be spaced at least one inch apart to prevent current overlap and skin discomfort.
Targeted Placement for Migraine Relief
Targeting migraine pain requires stimulating specific cranial nerve pathways, most notably branches of the trigeminal and occipital nerves. Placement focuses on sites where these nerves are most accessible near the skin surface. One common method involves placing a single electrode on the forehead, specifically over the supraorbital nerve, a branch of the trigeminal nerve.
A different approach targets the greater occipital nerve at the back of the head, similar to tension headache placement. Placing electrodes on the mastoid process, the bony prominence just behind the ear, is another effective strategy for some individuals. This area can be targeted in combination with an electrode placed lower on the jaw or neck, depending on the side where the migraine pain is felt.
Placement may involve using commercially available devices designed for the forehead, which deliver precise micro-pulses to the trigeminal nerve. When using a standard TENS unit on the face, avoid placement directly over the eyes or inside the mouth. Experimenting with placement near the pain source is often necessary for optimal relief.
Recommended Intensity and Session Timing
Once the electrodes are positioned, the TENS unit settings must be adjusted to deliver effective stimulation without causing pain. Intensity should be gradually increased until a strong, comfortable tingling or buzzing sensation, known as paresthesia, is felt. The sensation should be below the level that causes any muscle twitching or contraction, which is generally considered too high for pain relief.
For acute headache pain, a high-frequency setting, typically 80 to 120 Hertz (Hz), is used. This setting utilizes the gate control theory of pain by flooding the nervous system with signals that override pain transmission. Conversely, for chronic or preventative treatment, a lower frequency setting, sometimes between 2 and 10 Hz, may be used to promote the release of endorphins.
A typical session duration for headache relief ranges from 20 to 40 minutes. Some research suggests that 30 minutes of treatment is beneficial for relieving migraine symptoms. Users are advised to start with the shortest duration and gradually increase the time as tolerated. Experts recommend a maximum of one hour per session to prevent skin irritation.