Electrotherapy is a treatment method that can help reduce acute and chronic pain.  It may be especially helpful immediately following an injury.  Electrotherapy involves stimulating nerve fibers with small electrical currents.  The electrical stimulation may promote the release of natural pain killing chemicals, called endorphins, or block pain signals to the brain.
 
Electrotherapy may be delivered by a doctor or licensed therapist.  Most types of electrotherapy methods deliver the electrical stimulation through pads that are adhered to the skin.  Batteries or an electrical outlet powers the devices.  Electrotherapy is usually used in the early stages of pain management treatment.  It may be combined with heat therapy, cold therapy, and manipulations or exercise to optimize the treatment benefit.

Electrotherapy is not painful.  You may feel mild stinging following your treatment.  There are several types of electrotherapy, which vary in frequency, waveform, and effect.  Transcutaneous electrical stimulation (TENS), percutaneous electrical stimulation (PENS), interferential current (IFC), and galvanic stimulation (GS) are common types of electrotherapy.
 
TENS units may be used in the clinic or you may be instructed on how to use one at home.  TENS therapy may be tolerated for hours, but the pain relief benefit lasts for a shorter period of time.  PENS is a newer electrotherapy method that is similar to TENS.  PENS uses very thin acupuncture-type needles.  It may be more uncomfortable and tolerated for a shorter period of time than TENS, but it results in a longer period of pain relief.
 
IFC is a deeper form of TENS.  It delivers a high frequency waveform that penetrates the skin more deeply.  It may be used to target deeper causes of pain.
 
GS provides a direct current that creates an electrical field over the treated area that affects blood flow.  It is most frequently used for acute injuries from major trauma that have bleeding or swelling.  It may also be used to treat low back pain or muscle spasm.  With GS, the positive pad sends signals to help reduce swelling.  The negative pad increases circulation and may improve healing.