Noninvasive macro- and microcirculatory tests provide quantitative information that offers answers to most questions posed in venous diseases. Duplex scanning is used to assess the macrocirculation, and microcirculatory methods are used to assess and quantify venous microangiopathy. Laser Doppler flowmetry is used to assess perfusion. Transcutaneous Po(2) and Pco(2) measurements are used to study venous hypertension, and strain-gauge plethysmography is used to assess capillary filtration. In venous hypertension, fluid filtration into the extracapillary compartment is increased. The increase in filtration is associated with a decreased venoarteriolar response. To quantify capillary filtration, two methods have been developed: venous occlusion plethysmography and rate of ankle swelling. These methods quantify filtration into the extracapillary compartment and, therefore, are an indication of the formation of edema, the most frequent sign in venous hypertension. Other methods, such as the vacuum suction chamber and the edema tester, can be used to assess changes due to treatments in venous hypertension. The techniques described in this article should be used in controlled environmental conditions