1) Lymphatic: Filariasis, Pressure by growths like tumours, Radiation, Chronic lymphangitis 2) Traumatic: Bruises, Sprains, Fractures 3) Infections: Cellulitis, Boils, Carbuncles 4) Metabolic: Gout 5) Venous: Varicose veins, Venous thrombosis 6) Hereditary: Milroy's disease