In capacitive diathermy, what happens to the treated body part?

• A. It becomes part of the electrical circuit
• B. It becomes magnetized
• C. It is cooled rapidly
• D. It emits photons

Answer: (A)

In capacitive diathermy, the device delivers an alternating electrical current through two plates with the body part placed between them, so the treated area becomes part of the electrical circuit. The current passes through tissue and heats it due to the tissue’s electrical resistance, producing localized warming. This heating occurs because of resistive (ohmic) heating in the tissues as the energy flows through them.

The other options don’t fit the mechanism: the effect isn’t magnetization, it isn’t rapid cooling, and photon emission isn’t the intended therapeutic mechanism. The key idea is that the body part completes the circuit and heats from the circulating current through tissue impedance.