Definition
Deep vein thrombosis (DVT), also known as phlebothrombosis, is caused by an occlusive blood clot in a deep vein. The clot forms due to various disorders of the blood and vascular system, such as changes in blood composition, blood flow velocity or vascular wall. The signs of deep vein thrombosis are swelling, pressure pain and cyanosis of the affected leg.
Cyanosis is a bluish discoloration of the skin caused by a lack of oxygen. To clarify such symptoms or to avoid complications such as pulmonary embolism, a doctor should be consulted. Burning in the legs
Causes
Normally, the blood contains cells called platelets (thrombocytes) and clotting factors that serve to close vascular injuries and thus stop blood from leaving the vessel. The platelets and clotting factors must be activated by various factors or activate each other so that a blood clot is formed and closes the injury. However, if the cells or clotting factors are activated by various pathological processes in the body and thus form clots, sometimes even without injury, these clots can partially or completely block a vessel.
Blood can then no longer flow through the clogged vessel and it backs up. If the affected vessel is a deep leg vein, this leads to deep vein thrombosis. Three factors are important for the development of deep vein thrombosis, of which only one or all can be changed at the same time.
The first is damage to the inner vessel wall (endothelium). This vascular wall can be damaged by inflammation or trauma. As a result of this damage, coagulation-promoting substances become active, which lead to the formation of a clot.
This clot can be so large that it obstructs blood flow. However, it can also come loose and get stuck in a narrow spot during its migration through the veins, blocking the vessel so that blood can no longer flow. The second factor is a reduced blood flow velocity.
By slowing down the blood flow, the clotting factors have time to react with each other and activate themselves, even if there is no injury. This causes a blood clot to form, resulting in deep vein thrombosis of the leg. The blood flow can be reduced by various things.
For example, immobilization after an operation, varicose veins or external pressure on the legs can reduce the blood flow. Heat treatment can also slow down the blood flow. In this case the veins relax and become wider, so that the blood can no longer be transported quickly enough from the legs to the heart.
The last factor is a change in blood composition. The composition of the blood can be altered by hereditary diseases and thus lead to increased blood clotting. Furthermore, drug treatment can lead to an increased risk of clot formation.
These mentioned causes can also lead to pelvic vein thrombosis. This is problematic due to its asymptomatic course, which is why it can be detected too late. The last factor is an altered blood composition.
The blood composition can be altered by hereditary diseases and thus lead to increased blood clotting. Furthermore, drug treatment can lead to an increased risk of clot formation. These mentioned causes can also lead to pelvic vein thrombosis. This is problematic due to its asymptomatic course, which is why it can be detected too late.
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