Blood clots

Clot; Emboli; Thrombi; Thromboembolus; Hypercoagulable state

Blood clots are clumps that occur when blood hardens from a liquid to a solid.

  • A blood clot that forms inside one of your veins or arteries is called a thrombus. A thrombus may also form in your heart.
  • A thrombus that breaks loose and travels from one location in the body to another is called an embolus.

A thrombus or embolus can partly or completely block the flow of blood in a blood vessel.

  • A blockage in an artery may prevent oxygen from reaching the tissues in that area. This is called ischemia. If ischemia is not treated promptly, it can lead to tissue damage or death.
  • A blockage in the vein will often cause fluid buildup and swelling.
Thrombus

A thrombus is a blood clot that forms in a vessel and remains there. An embolism is a clot that travels from the site where it formed to another location in the body. Thrombi or emboli can lodge in a blood vessel and block the flow of blood in that location depriving tissues of normal blood flow and oxygen. This can result in damage, destruction (infarction), or even death of the tissues (necrosis) in that area.

Deep venous thrombosis, ileofemoral

This picture shows a red and swollen thigh and leg caused by a blood clot (thrombus) in the deep veins in the groin (iliofemoral veins) which prevents normal return of blood from the leg to the heart.

Causes