According to MedicineNet, blood clots form when blood platelets go to an injured area. Chemicals are released that cause a clotting cascade. Fibrin, which is a sort of mesh, is formed.
Blood clots form when blood fails to circulate adequately, according to MedicineNet. The medical term for a blood clot is "thrombosis." A thrombosis is often a healing process where the blood clot forms to repair the lining of damaged blood vessels.
MedicineNet explains that there are several types of blood clots. Arterial thrombi form when a plaque ruptures and promotes an acute clot. Venous thrombosis occurs when prolonged immobility allows blood to pool in an extremity and clot.
A thrombosis is diagnosed through history and a physical exam, says MedicineNet, and is often confirmed by a radiological test. Treatment includes surgery, anti-coagulation medications or a combination of both. Prevention includes attention to risk factors, such as vascular disease.
Deep venous thrombosis, or "DVT," is a sign of a potentially dangerous condition, according to MedicineNet. In this case, there is a blood clot deep in the vascular system. Symptoms include pain, swelling and redness, similar to an infection. The danger is that the blood clot could break off and float downstream to the lungs, getting lodged and causing lung failure.