Reflux cannot be interpreted without knowledge of the function of the calf muscle pump. The presence or absence of reflux alone has an insufficient predictive value for excellent functional treatment results. Valves are not simple moving slips but have an autonomous 4-step cycle movement that helps the calf muscle pump to be very effective. New calculations of the Starling equilibrium have shown that capillary filtration fraction returns mainly by the lymphatics. All these new findings help the phlebologist design a more precise and thus better treatment plan in phlebology practice.