Moist Heat and TENS Therapy


How to Use Moist Heat for Pain Relief

Applying moist heat, like a microwaveable heating pad,  is an easy, affordable, and safe way to obtain pain relief.  Heat should be used with caution.  A hot pack should be applied with additional toweling so that comfortable warmth is achieved without the potential for burns.  Heat can be applied any amount of time, but increased length of application can increase the risk for burns, especially when the heat source is constant, such as with a plug in heater.  Heat can also increase swelling in an injured area.
How Moist Heat Works to Reduce Pain

Moist heat has been shown to increase local metabolism and blood flow.  This can assist with increasing circulation to an area, in general allowing for increased nutrient flow to the area while helping to flush out pain substances.  Both of these processes can help to relieve pain.
Moist Heat Works Well with TENS Therapy

Moist heat can also aid in muscle relaxation by decreasing tissue tension and spasm while increasing tissue extensibility, which often assists in pain relief.  Heat can be used in conjunction with a TENS unit.  While TENS can be used for symptomatic pain relief, moist heat can add additional therapeutic benefits.  The electrical impulses from the TENS unit excite the sensory nerves.  This can provide varying degrees of pain relief by activating the body’s natural pain relieving system and/or the nervous system’s ability to use the electrical impulses to interfere with the pain messages being sent to the brain.
Moist Heat is Not Recommended for Everyone

People with certain conditions should also be very cautious when using heat.  Anyone with decreased skin sensitivity can be at increased risk for burns.  Increased inflammation and burns can occur in patients with Diabetes Mellitus, rheumatoid disorders, spinal cord injuries, and multiple sclerosis. Consult with a doctor before using heat if you have any questions or concerns.

By Kathleen Prampin, PT (Physical Therapist), MPT, OCS, Cert. MDT, COMT

Article Reference: “The physiologic basis and clinical applications of cryotherapy and thermotherapy for the pain practitioner” authored by Nadler, Weingand, and Kruse. Pain Physician  2004; 395-399