Diathermy << DY uh `thur` mee >> is a method of treating muscle and joint disorders and other diseases by creating heat energy in tissues beneath the skin. Diathermy is used chiefly to relieve such conditions as muscle aches, muscle strain, and pain and inflammation in the joints.
In diathermy, high frequency electromagnetic energy is passed through the body. The tissues of the body have different resistances to the flow of the electromagnetic energy. This resistance causes a temperature rise in the tissues. The heat produced affects the tissues, resulting in healing, relief for sore muscles and joints, soothing of inflammation, and other therapeutic effects. The main benefit of diathermy over other treatments that apply heat, such as hot packs, is the depth of heat penetration. Diathermy can generate heat deep within muscle and other tissues of the body.
The electromagnetic current used in diathermy is an oscillating (back-and-forth moving) current. There are several forms of diathermy, each with the electromagnetic current oscillating at a different range of frequencies. Short-wave diathermy, with frequencies in the range of radio waves, is the most commonly used form. This diathermy is usually applied with two insulated metal plates, which fit against the part of the body treated. Short-wave diathermy can be applied either continuously or in pulses. Pulsed short-wave diathermy (PSWD) is more popular because it produces heat at a slower rate and is more comfortable for the patient.
