Clinical Spectrum of Clotting

The signs and symptoms of blood clots range from deep vein thrombosis to pulmonary embolism. The symptoms of a blood clot depend on the location of the affected blood vessel and whether the vessel is totally or partially blocked by the clot.

Deep Vein Thrombosis

Blood clots may form in the deep blood vessels, most commonly in the legs and groin, and can block normal blood flow returning from the legs to the heart. Clots in the veins that form in regions of slow to moderate flow are made of a mixture of red cells, platelets, and fibrin, and are known as mixed platelet fibrin thrombi.

Clots in the deep veins of the legs or abdomen that partially block the vein may cause subtle symptoms and sometimes may not cause any symptoms until the normal blood flow is significantly disturbed.

Learn the signs of deep vein thrombosis

Pulmonary Embolism

A pulmonary embolism occurs when a part or all of a deep vein clot breaks loose and is carried by the bloodstream to the lungs, where it blocks another blood vessel.

The size of the clot and the location of the blocked blood flow in the vessel determine the extent and severity of the pulmonary embolism. Clots in veins that are closer to the body center are more likely to lead to deadly pulmonary embolism as compared to clots in the calf veins.

The occurrence of deadly pulmonary embolism can be greatly reduced if the patient’s deep vein thrombosis is treated with blood thinners.

Learn the signs of pulmonary embolism

Superficial Vein Swelling

Superficial swelling of the veins, called thrombophlebitis, is the result of blood clots that form in veins that are closer to the surface of the skin. These are associated with inflammation. Superficial thrombophlebitis is often observed in individuals who are heterozygous or homozygous for the factor V Leiden mutation.