Some patients will respond better than others and the number of treatments for each vessel may depend on the darkness and size of the vessel as well as the amount of activity the patient undergoes post-treatment. Vessels treated on the legs have a higher tendency to resurface, as the blood pressure tends to be higher. After treatment, a rust-colored staining of adjacent skin tissue, called hemosiderin, may appear from the breakdown of hemoglobin and will subside over the course of 3-4 weeks.