Biophysical effects of diathermy include which of the following?

• A. Increase blood flow
• B. Activation of fibroblasts
• C. Increase macrophage activity
• D. All of the above

Answer: (D)

Diathermy works by heating tissues with electromagnetic energy, and that heating triggers several coordinated responses at the cellular and tissue level. The rise in temperature causes vasodilation, which increases blood flow and improves delivery of oxygen and nutrients while helping remove wastes. Heat also signals fibroblasts to become more active, boosting collagen production and matrix remodeling crucial for tissue repair. At the same time, the higher metabolic rate from heating enhances immune cell function, including macrophages, which aids debris clearance and local defense. Because these heating-induced changes commonly occur together with diathermy, all of these effects are observed biophysical responses to the treatment.