As I understand it the biggest culprit in DVT is dehydration, lack of Oxygen, lack of movemnent or sitting motionless for hours at a time, while drinking coffee or tea which exacerbates the problem
Being overweight some say yes and others say no, one Vascular Surgeon I spoke to was on the NO side.
But if you had recent major surgery then the formation of a DVT is high within the 3 months or so, so now there seems a policy to have patients on Warfarin pills while they are in hospital lying motionless to prevent DVT forming.
But what has been expressed on this thread is valid, plenty of water and keep moving, but one day when you are giving blood for some test, get a thromphilia test and see if you are predisposed to blood clotting.
But remeber that DVT can be dangerous and in some cases it can be fatal, so take it seriously.