When the normal mechanisms of venous blood flow from the legs fail ‘venous insufficiency’ develops, which manifests in many ways. At its most mild venous insufficiency causes spider veins which are by and large cosmetic problems only, but can be associated with aching. Slightly larger bluey veins can also result which lie slightly deeper and are called reticular veins. More severe failure causes the common varicose veins and in 1-2% of the population over 65yrs skin changes and ulcers will result. All these are due to high pressure developing in thin walled veins which are designed to withstand low pressures only. Venous insufficiency can be caused by 1.Deep vein obstruction 2.Muscle pump failure 3.Valve failure Deep vein obstruction can be caused by DVT (Deep venous thrombosis) eg in economy class syndrome or by tumours in the pelvis compressing the veins. If it persists it causes valve failure too.