<s>[INST] I had an engorged vein pop up on the top backside of my right leg just under my knee. It was very painful, burned and stung. After a bit the engorged vein slowly went down and now I have a very large deep purple bruise. At the same time I also had the same thing happen to another vein on the outer side of that leg. Should I be concerned? [/INST] Hi. Thanks for reaching out. Based on the description you have mentioned, it sounds like you have varicose veins. These are seen because of faulty vein valves. This can cause the size of the veins to increase. Varicose veins are treated by using compression socks, raising the legs high, and rarely surgery may be suggested to treat this. Seeing a surgeon would be a good idea. I hope this helps! All the best. </s>