Could be either. Technically, phlebothrombosis means a blood clot in a vein without inflammation. It is a term that we don't see being used very often these days. Thrombophlebitis means inflammation of a vein with a clot. Generally, when one gets a dvt, a clot forms that causes the vein to become inflamed and painful. If a DVT occurs that isn't painful, it is more likely to be a phlebothrombosis. Clear as mud?