What are blood clots?
Blood clotting is a natural process to stop bleeding after an injury. Blood does not normally clot in the circulation, but can in some medical conditions. The medical term for a blood clot in the circulation is a thrombus or thrombosis.
Types of clots
Clots can form in arteries or veins. Blood clots that block arteries cause heart attacks and strokes. Clots in veins cause deep vein thrombosis and pulmonary embolus.
The information on this web-site is about clots in veins.
Clots in veins
A clot in a vein is called a venous thrombosis. These clots may be in superficial veins or deep veins.
Superficial vein thrombosis
- These form in veins just under the skin.
- They can cause a local area of tenderness.
- Often the skin becomes red and hot over the clot.
- The condition is sometimes called superficial phlebitis
Deep Vein Thrombosis
- These clots form in veins deep inside the leg. The veins involved cannot be seen.
- These most commonly form in the leg veins but can occur in other parts of the body such as the arms or intestines.