Shall i see my doctor about a bruised vein?

Several Things.: The most common cause of veins bursting and bleeding would be trauma. Other causes could be the taking of blood thinners such as Coumadin (warfarin) but also nsaids, aspirin, fish oil, flaxseed oil, plavix, etc.Another cause could be blood problem resulting in an inability to clot. Obviously, it is impossible to make a diagnosis based on only a few facts. You should see a hematologist if bruising recurs.