This document summarizes chronic venous insufficiency (CVI), which occurs when veins cannot pump enough deoxygenated blood back to the heart. CVI mainly affects the legs and can cause varicose veins, spider veins, and reticular veins. The venous system includes deep, superficial, and perforating veins. Symptoms of CVI include leg pain, swelling, skin changes like eczema. Risk factors include age, gender, heredity. CVI can lead to complications like ulcers and thrombophlebitis if left untreated. Diagnosis involves tests like Doppler ultrasound and treatment options include compression stockings, sclerotherapy, and surgery to remove or occlude veins.