Blood clotting is a natural process in which blood cells and fibrin strands rapidly form a clump to stop bleeding after a blood vessel has been injured. Eventually the clot will form a protective scab over a wounded blood vessel, allowing it to heal. If the body did not have the ability to form blood clots, people would bleed to death after even a minor cut.

Sometimes, however, blood clots form even when a person has not been injured. Although most blood clots tend to dissolve on their own with no long-term problems, there are situations in which blood clots can cause medical problems. Blood clots become dangerous when they block blood flow through an artery or vein.

When a blood clot blocks blood flow to an artery in the heart or brain, a heart attack or stroke may result. Blood clots can also block veins and arteries throughout the body, causing diseases that range from varicose veins to a life-threatening pulmonary embolism.

Physicians treat blood clots with a variety of methods. Medications such as anticoagulants (which help prevent blood clots) and clot busters (which help to dissolve blood clots) are prescribed to prevent and treat blood clots. In more serious situations, physicians might opt for a catheter-based procedure, which uses a long, thin tube called a catheter, or even surgery to remove the clot (thrombectomy). In addition, devices may be implanted into certain blood vessels to catch blood clots before they can cause serious damage.