Varicose veins are caused by poorly functioning valves in the veins, and decreased elasticity of the vein wall, allowing pooling of blood within the veins, and their subsequent enlargement. Varicose veins affect up to 40% of adults, and are more common in obese people, and in women who have had more than two pregnancies.We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments in adults with varicose veins? We searched: Medline, Embase, The Cochrane Library and other important databases up to January 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).We found 39 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.In this systematic review we present information relating to the effectiveness and safety of the following interventions: compression stockings, endovenous laser, injection sclerotherapy, radiofrequency ablation, self-help (advice, avoidance of tight clothing, diet, elevation of legs, exercise), and surgery (stripping, avulsion, powered phlebectomy).