What Is Microwave Diathermy?

Medical professionals often use microwave diathermy equipment, which produces electromagnetic radiation that generates heat in body tissues. It one of the commonly used types of diathermy, which also includes shortwave diathermy and ultrasound. Trained personnel generally use diathermy as only one of the components of a therapy regimen, and microwave treatment cannot be used in the presence of active infections, pregnancy, or metal implants. Side effects of microwave diathermy include the possibility of developing skin burns from heated perspiration.

Diathermy machines generally consist of a power source that sends electrical current into a magnetron, a tube-like structure with exterior magnets. The combination of the electric current and the magnetic field produces microwaves, which lie between the wavelength of radio waves and infrared radiation. Attached to the exterior of the machine cabinet are one or two adjustable arms, each having an end applicator. The round or rectangular applicator has a flat surface on one side that acts as an antenna through which the microwaves travel. The machine emits microwaves in either a continuous or pulsed mode at a frequency of either 915 megahertz or 2,456 megahertz.

Personnel also control the width of the emitted beam, concentrating the microwaves on designated areas, where the radiation excites the molecules in the fluids of the tissue. The effects of microwave diathermy include heat development as the molecules move at an increased rate of speed. Studies indicate that within five to ten minutes, fluid temperature rises up to four degrees higher than normal. Therapists also believe microwaves penetrate tissue more deeply, producing heat in soft tissue more effectively than conventional warm packs.

When the fluid in tissues is heated, vascular structures relax, increasing blood flow. Therapists suggest that enhancing circulation of affected areas flushes inflammatory chemicals, bradykinin, and histamine, from injury sites.The elevated temperature also increases cellular replication and repair processes by increasing available nutrients and oxygen. Other benefits of microwave diathermy include relaxation of connective and muscle tissue, which increases mobility and reduces muscle spasms. The heat also alters nerve tissue excitation, which reduces pain signals received by the brain.

Chiropractors and physical therapists may direct microwave diathermy treatments toward subcutaneous tissues located anywhere on the limbs or torso. Patients typically receive diathermy for 20 to 30 minutes as treatment for arthritis in the hands or feet, soft tissue injury, and wound healing. Research indicates that microwave diathermy also significantly decreases the pain and other symptoms in women diagnosed with dysmenorrhea. Some therapists also use microwave diathermy in the treatment of psoriasis.