There are many types of electrical therapy to treat pain and other conditions. Most incorporate the use of electrical currents to stimulate muscles or nerves and cause little or no discomfort. They include:

• Transcutaneous electrical nerve stimulation (TENS). A small, battery-operated device sends low-voltage electrical current through the skin, with electrodes (small, flat adhesive discs) placed near the source of the pain. The electricity stimulates the nerves in the affected area and sends signals to the brain that distort normal pain signals. TENS, the most common type of electrical therapy, can sometimes be performed at home by patients who have received training from a physical therapist or other healthcare professional.
  
  
• Percutaneous neuromodulation therapy (PNT). Also known as percutaneous electrical nerve stimulation (PENS), PNT is similar to TENS except that needles are inserted in the area where pain is being experienced before stimulation occurs. This may be used with patients who have difficulty getting adequate electrical stimulation with TENS because of obesity, scar tissue or other issues.
  
  
• Electroacupuncture. This treatment is sometimes described as a variation of PNT and sometimes as a separate therapy. It incorporates techniques of acupuncture with needles that are inserted on specific points in the body. The needles are then attached to a device that generates electrical pulses. This technique has been used to treat a wide variety of chronic pain conditions, including heartburn, a common cause of chest pain. Auriculotherapy is a type of electroacupuncture in which the external ear is stimulated with electrical currents.
  
  
• Microcurrent electrical therapy (MET). Electrodes are placed on opposite sides of the body so that the electrical current flows through the injured or diseased part of the body and speeds healing.
  
  
• Iontophoresis. Electrical current delivers medication through the skin. This method is sometimes used to treat conditions such as neck pain, back pain, arthritic conditions, rotator cuff injuries, bursitis, tendinitis and other joint pain. (A similar technique called phonophoresis uses ultrasound instead of electricity to introduce medication through the skin.)
  
  
• Intradiscal electrothermal therapy (IDET). A wire is placed into an injured intervertebral disc. The wire is then electrically heated to seal and toughen the tissue. It is often used to treat lower back pain.
  
  
• Spinal cord stimulation (SCS). Electrical impulses are used to block pain from being perceived in the brain. A small wire connected to a power source is surgically implanted under the skin. Low-level electrical signals are transmitted to the spinal cord. This is sometimes used to treat chronic back pain.
  
  
• Occipital neurostimulation (ONS). Minimally invasive surgery inserts electrodes beneath the skin at the base of the skull. ONS has been used to treated severe head pains including migraines and neuralgias.
  
  
• Galvanic stimulation (GS). This is used to treat acute injuries. Unlike other types of electrical therapy that use alternating currents, GS uses direct current, which changes blood flow and speeds healing.
  
  
• Russian stimulation. This type of electrical muscle stimulation provides deep penetration and intense contraction. This method is most often used to treat spinal cord injuries, scoliosis and chronic muscular pain conditions.

• Shortwave diathermy. A high-frequency electrical current raises the temperature in body tissues. This increases elasticity in connective tissue (particularly skin), muscles, ligaments and joint capsules. Conditions it is used to treat include arthritis, bursitis, sinusitis, tendinitis, contusions, ruptures and fractures.

• Transcutaneous electrical joint stimulation (TEJS). Electricity is delivered through electrodes worn for hours a day in an effort to ease knee osteoarthritis.
  
  
• Interferential electrical stimulation (IFC). This can be used on deep tissues, such as the pelvic floor muscles, that do not respond to other types of electrical therapy. It may require using a greater number of electrodes and take longer to perform than other types of electrical therapy.
  
  
• Sympathetic therapy. This technique attempts to ease widespread chronic pain by stimulating the sympathetic nervous system and returning the autonomic nervous system to normal.
  
  
• Cranial electrotherapy stimulation (CES). Electrodes are placed behind the ear or clipped to the upper portion of the earlobe, near the face. CES works by increasing the production of endorphins (hormones found mainly in the brain that reduce pain and affect emotion). It is used in the treatment of anxiety, depression, insomnia and drug addition.
  
  
• Functional electrical stimulation (FES). This technique is used to produce movement in paralyzed muscles. Electrodes are placed on muscles and contracted in a controlled manner. It is used to treat spinal cord injury, stroke, multiple sclerosis and cerebral palsy. This is also called peripheral nerve stimulation (PNS).
  
  
• Neuromuscular electrical stimulation (NMES). A device sends electrical impulses via electrodes to activate underused muscles.
  
  
• Vagus nerve stimulation (VNS). A surgically implanted device delivers electrical impulses to the brain. VNS has been studied in addressing conditions including hard-to-treat major depression.
  
  
• Deep brain stimulation (DBS). An electrode is inserted into the brain to stimulate a region called the thalamus. DBS has been used to treat movement disorders such as Parkinson’s disease, essential tremor and dystonia.
  
  
• Gastric pacemakers. Similar in some ways to cardiac pacemakers, these surgically implanted devices are being developed as a way of making obese people feel full and eat less. obesity contributes to many pain conditions including abdominal pain, chest pain, back pain and osteoarthritis.