Thrombus
Blood clot / From Wikipedia, the free encyclopedia
A thrombus (pl. thrombi), colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of cross-linked fibrin protein. The substance making up a thrombus is sometimes called cruor. A thrombus is a healthy response to injury intended to stop and prevent further bleeding, but can be harmful in thrombosis, when a clot obstructs blood flow through a healthy blood vessel in the circulatory system.
Thrombus | |
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Other names | Blood clot |
Diagram of a thrombus (blood clot) that has blocked a vein valve | |
Specialty | Vascular surgery |
Symptoms | abrupt change in mental status, chest pain, cramp-like feeling, fatigue, passing out (syncope), and swelling in the arm and/or leg |
Complications | bleeding risks from taking anticoagulants, breathing problems, heart attacks, stroke |
Duration | c. 3–6 months |
Types | Superficial thrombophlebitis and thrombophlebitis migrans |
Causes | injury to the artery, sepsis or viral infection, immobility |
Risk factors | hospitalization, immobility, obesity, pregnancy, physical trauma |
Diagnostic method | magnetic resonance angiography, ultrasound, and venography |
Prevention | smoking cessation, regular exercise, improved blood flow, management of comorbidities |
Treatment | Anticoagulants: edoxaban, tinzaparin, unfractionated heparin |
Medication | apixaban, edoxaban, and rivaroxaban |
Deaths | 100,000–300,000 each year |
In the microcirculation consisting of the very small and smallest blood vessels the capillaries, tiny thrombi known as microclots can obstruct the flow of blood in the capillaries. This can cause a number of problems particularly affecting the alveoli in the lungs of the respiratory system resulting from reduced oxygen supply. Microclots have been found to be a characteristic feature in severe cases of COVID-19 and in long COVID.[1]
Mural thrombi are thrombi that adhere to the wall of a large blood vessel or heart chamber.[2] They are most commonly found in the aorta, the largest artery in the body, more often in the descending aorta, and less often in the aortic arch or abdominal aorta.[2] They can restrict blood flow but usually do not block it entirely. They appear grey-red along with alternating light and dark lines (known as lines of Zahn) which represent bands of white blood cells and red blood cells (darker) entrapped in layers of fibrin.[3]