Impedance plethysmography is primarily used to assess which condition?

• A. Venous disease
• B. Arterial disease
• C. Neurological impairment
• D. Lymphedema

Answer: (A)

Impedance plethysmography measures how limb blood volume changes as veins fill and empty, so the signal mainly reflects venous function. That makes it a tool best suited to evaluating venous disorders—how well the veins drain, whether there is reflux, or if venous outflow is impeded—such as in chronic venous insufficiency or suspected DVT. It isn’t the go-to method for arterial disease, which is typically assessed with Doppler ultrasound and pressures, nor is it the primary test for neurological impairment. Lymphedema is a lymphatic concern, not venous, so impedance plethysmography isn’t the standard method for that condition. So, the primary use is to assess venous disease.