180 degrees. Arterial thrombosis is stoppage of blood flow from the heart to different parts of the body. The result is tissue death: in arteries to the heart=heart attack; in arteries to the legs=gangrene. Venous thrombosis is within veins which return blood to the heart. It may be in deep veins which is a serious matter often requiring anticoagulation, and in superficial veins appearing red, painful.
Location. The main difference is location, one is on the venous side, the other on the arterial side. Causes of thrombosis are usually different on the venous side than on the arterial side but there are some disease states that can produce thrombosis on either side. A common cause on the arterial side is atherosclerosis, a common cause on the venous side is stasis producing a deep venous thrombosis (dvt).
Location and flow. Arteries carry blood, oxygen, and nutrients from the heart to the rest of the body. If an artery thromboses (usually from atherosclerosis) the tissue supplied can die for lack of oxygen. Veins drain blood from the body back to the heart. If a vein thromboses, the greatest risk is of a clot breaking off and traveling to the heart and lungs, where it can block blood flow through the lungs.
Throbosis=clot. A thrombosis is a blood clot. The veins are redundant meaning that there are a lot of them draining a certain area. So a venous thrombosis is usually not really important except for discomfort as long as it is in the surface veins. One in the deep veins is a medical emergency. The arteries are less redundant and a clot in an artery can damage the area it supplies and can be very serious.
Very different. Venous thrombosis is often painful and can cause swelling in the legs, but is rarely life or limb threatening unless associated with pulmonary embolism. Arterial thrombosis however is almost always a vascular emergency. Without adequate artery circulation, the end organ (leg, arm, kidney, brain, heart) begins to suffer and tissue begins to die. If treated quickly, recovery is possible.
Different outcome. Arterial thrombosis occurs when there is stoppage of blood flow in an artery due to arteriosclerosis or embolus. The part that is fed by the artery is injured by the lack of blood supply. Venous thrombosis comes on after there is stagnant flow, injury to the vein lining, and abnormalities in blood components. There is local pain, but rarely tissue injury.
Depends on extent. In the acute setting arterial thrombosis can result in profound ischemia of the target organ. For example, acute thrombosis of a leg artery may lead to a leg that dies or a stroke may occur if the carotid artery acutely thromboses. Because veins drain an organ, acute thrombosis usually results in swelling. If bad enough the swelling may result in ischemia as well by causing a backup in flow.