Blood clots are the clumps that occur when the blood hardens from a liquid to a solid (coagulates). A blood clot that forms inside a blood vessel or within the heart and remains there is called a thrombus.

A thrombus that travels from the blood vessel or heart to another location in the body is called an embolus. The disorder is called an embolism. For example, an embolus that occurs in the lungs is called a pulmonary embolism.

Sometimes other materials can act like an embolus and block blood flow, including:

• Air
• Amniotic fluid
• A piece of atherosclerotic plaque
• Fat clumps
• Small pieces of tumor

See also:

• Angina
• Arterial embolism
• Atheroembolic renal disease
• Deep venous thrombosis
• Heart attack
• Pulmonary embolism
• Renal vein thrombosis
• Stroke
• Thrombophlebitis

Clot; Emboli; Thrombi