Diathermy and radiation improve which type of drainage?

• A. Lymphatic drainage
• B. Venous drainage
• C. Vascular drainage
• D. Interstitial drainage

Answer: (C)

Heating with diathermy or infrared radiation raises tissue temperature, which causes arteriolar dilation and increased local blood flow. This boosts venous return from the treated area, helping move fluid and metabolic byproducts through the vascular system. So, the primary drainage improvement from these modalities is vascular drainage. Lymphatic drainage is typically targeted by lymphatic-focused techniques, and interstitial drainage refers to fluid in the tissue spaces, which is not the main effect of this heating.