Which therapeutic modality uses high-frequency electric current to generate heat within body tissues?

Which therapeutic modality uses high-frequency electric current to generate heat within body tissues?

• A. Infrared
• B. Whirlpool
• C. Diathermy
• D. Ultraviolet

Answer: (C)

Diathermy heats tissues from within by using high‑frequency electric current. Devices deliver current that tissues resist, so the power dissipates as heat inside the body (I^2R heating). This allows deep, uniform warming of muscles and deeper connective tissues, aiding flexibility, circulation, and pain relief. Infrared heats mainly from the outside through radiant energy, so warming is surface-focused. Whirlpool involves warm water and hydrotherapy, providing heat and buoyancy effects largely at the surface and through circulation. Ultraviolet uses UV light to affect skin cells, not to heat deep tissues.

Diathermy heats tissues from within by using high‑frequency electric current. Devices deliver current that tissues resist, so the power dissipates as heat inside the body (I^2R heating). This allows deep, uniform warming of muscles and deeper connective tissues, aiding flexibility, circulation, and pain relief.

Infrared heats mainly from the outside through radiant energy, so warming is surface-focused. Whirlpool involves warm water and hydrotherapy, providing heat and buoyancy effects largely at the surface and through circulation. Ultraviolet uses UV light to affect skin cells, not to heat deep tissues.