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Blood Clots

Blood clots facts

  • Blood clots form routinely as a normal function of blood cells to repair damaged blood vessel walls. Blood clots become a problem when the blood "clots" in an artery or vein inappropriately prevent blood from flowing through those blood vessels
  • Risk factors for developing blood clots in arteries include high blood pressure, high cholesterol, diabetes, smoking, and family history of forming blood clots.
  • Risk factors for developing blood clots in veins include prolonged immobility (including immobility after surgery), hormone therapy (including birth control pills), smoking, pregnancy, and genetic factors.
  • Causes of arterial blood clots include atherosclerosis plaques ruptures, as in a heart attack. A clot embolus can block (occlude)  an artery after it travels from one part of the body to another, for example, a stroke can occur from a  blood clot that originates in the heart.
  • Causes of venous blood blots include immobility, where the blood stagnates and begins to clot. For example, a blood clot forms in the leg from lack of activity from prolonged travel in a car, train, plane or being bedridden after surgery.
  • Signs and symptoms of blood clots depend upon their location and whether they occur in an artery or a vein. A blood clot in an artery that supplies blood to the heart or brain may result in
    • heart attack,
    • stroke, or
    • TIA (transient ischemic attack or mini-stroke)
  • When blood clots occur in a vein, symptoms may include
    • pain,
    • swelling,
    • warmth, and
    • redness.
  • If a forms in a vein in a leg or arm breaks off and travels to the lung, it causes  a pulmonary embolus, a potentially life threatening condition can occur. Symptoms of pulmonary embolism are
  • Blood clots are diagnosed initially by history and physical examination. Other tests may be ordered depending upon the location of the blood clot.
  • The treatment for blood clots depends upon the location, but most situations require the use of anticoagulant medications that thin the blood, and prevent further clots.
  • Medications used for blood clot treatment thin or anticoagulate the blood.
  • Complications of blood clots often depend upon their location.
  • Blood clots can be prevented by remaining active, especially after surgery; quitting smoking, especially if a woman takes birth control pills; and life-long control of high blood pressure, high cholesterol, and diabetes.
  • The prognosis for a person with a blood clot depends upon the health of the person, the location of the blood clot, and how quickly medical care is accessed.

What does a blood clot look like?

Picture of blood clotting
Picture of blood clotting
Last Reviewed 8/30/2017

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Blood Clots - Treatment

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Blood Clots - Signs and Symptoms

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Deep Vein Thrombosis (DVT) Symptoms and Signs

Symptoms of a blood clot in the leg (deep vein thrombosis or DVT) occurs when a clot clogs the blood flow in a vein, causing inflammation. Examples of symptoms and signs of a DVT in a leg are:

  • Swelling
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