Diatermia

Diatermia, also known as diathermy, refers to the therapeutic heating of body tissues using high-frequency electromagnetic energy. The term derives from Greek dia "through" and therme "heat." In medicine, diathermy encompasses both methods to raise tissue temperature for therapeutic purposes and surgical techniques that use high-frequency currents to cut or coagulate tissue.

Two principal forms are shortwave diathermy (SWD) and microwave diathermy (MWD). SWD uses radiofrequency energy in the shortwave band (roughly 3–30 MHz) delivered by inductive coils or capacitive plates to produce deep heating. MWD uses microwaves (about 0.9–2.5 GHz) for dielectric heating, typically more superficial. A surgical form, electrosurgical diathermy, uses high-frequency currents to cut or coagulate tissue during operations.

Therapeutic uses aim to relieve pain, improve tissue extensibility, and promote healing as part of physical therapy. Surgical diathermy is used to cut tissue and control bleeding during operations. The modality may be applied with patient monitoring and temperature controls to avoid overheating and unintended tissue damage.

Safety and contraindications: diathermy can cause burns if skin temperatures rise too high and may interfere with implanted devices such as pacemakers; it should be used with caution near pregnancy areas, eyes, or testes, and in the presence of active infections or cancer in the treatment field. Proper screening, device calibration, shielding, and temperature monitoring reduce risk.