Blood Clotting and Thrombosis Explained

As a child in the primary school, I was taught that when I have injuries in my arm while playing, my blood will cover it for me. My teacher didn't explain the process to me, but she gave me an idea that my blood was doing more than just circulating round my body. In my junior secondary education, my teacher made it clear that the blood platelet was responsible for blood clotting when I have an injury or break in my skin. So, I am no more in primary school or secondary school. In fact, a friend and I have worked on analyzing blood, and now, I know better about blood and blood clotting.

I need to say clearly that contrary to what my elementary teachers told me about blood clotting being a good thing, we need to know that blood clotting has both the good and the bad side, so I will be doing justice to that today.

Blood Clotting (Thrombus) Formation

Blood Clotting/Thrombus is composed of thrombocytes, fibrin and red blood cells (for oxygen). It is a common process in cases of vessel injury from accidents and other types of bruises where blood platelet along with red blood cells quickly gets to the injured site and create platelet plugs. At the same time, a coagulating enzyme called Thrombin, converts fibrinogen into fibrin in the platelet plug, forms a blood clot in the red blood cell called Fibrin Mesh Clot.

Blood Clotting Go Wrong (Thrombosis)

Above, I explained the process of blood clotting, and it looked good, With Thrombosis, blood clotting doesn't happen in the site of an injury. Blood clots in the blood vessel (Artery/vein) without a cut. Risk factors for Thrombosis are immobility, heart attack or stroke, taking birth control pills when pregnant, leg paralysis, fracture, Disease or injuries to veins and arteries without a break outside the skin, and many more.

Thrombus can occur as a result of three factors, which are regarded as the Virchow's triad. Thrombus can occur due to intravascular vessel wall (endothelium) damage, stasis (sudden change) of blood flow, and hypercoagulable of blood. Thrombus inside the vein or artery can exist as mural thrombus and Occlusive Thrombus. Mural Thrombus are clot or thrombi, attached to the wall of a blood vessel (aorta), or the chamber of the heart. Occlusive Thrombus is a blockage of the blood vessel by a clot. Blood clots or anything moving freely in the blood vessel without blockage with the potential of causing a blockage is called an Embolus and the process is Embolism. Embolism can occur in the vein and artery as venous thromboembolism, and arterial thromboembolism.

Deep Vein Thrombosis has to do with thrombi in the deep veins of the body (the legs). The leg usually suffers thrombosis because it takes more than the heart to move blood from the legs to the heart. Blood movement from the legs to the heart involves more than the heart contraction, it involves the leg muscle contraction, thereby squeezing the blood through the deep veins in the legs. Deep vein Thrombosis can occur due to prolong sitting, and lack of movement of the leg muscles.

Deep vein Thrombosis usually come with swelling, and pains when weight it put on it (in legs). Usually, this blood clot always embolize, taking the blood clot from the leg to the heart which could cause pulmonary embolism. When the blood clot, gets to the right Atrium, of the heart, then moves to the right ventricle of the heart, where it is pumped to the lungs through the pulmonary artery. The Thrombi block the pulmonary artery of the lungs, causing lung damage known as pulmonary embolism, which would lead to lesser oxygenated blood. This would lead to the heart overworking itself in other to provide the necessary blood needed to the body, which could lead to cardiac arrest, which could lead to death in severe cases.

It is a different case when the embolism is in the artery. This goes directly to the brain, causing stroke or transient ischaemic attack. It is often as a result of Atrial fibrillation (A-fib), a state where the atrial of the heart is beating irregularly, not syncing with the ventricle causing blood clot in the heart. The left ventricle pumps blood to the aorta sends blood to the left common carotid artery, and left subclavian artery which supplies blood to the upper part of the body which includes the neck and the head. When there is an embolus in the artery, it moves to the brain, blocking the cerebral artery or the carotid artery and can lead to stroke.

Conclusion

Treatment for thrombusis would be anticoagulants (blood thinner), which would prevent further blood clotting. Blood clot could be removed surgically.

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• John Hopkins Medicine - Thrombosis

• What is Thrombosis?

• Visualdx - Mural thrombus

• National Library of Medicine - Mural Thrombi

• National Library of Medicine - Occlusive thrombosis in arteries

• Hematology - Blood Clots

• Med broadcast - Embolism

• What Is Thromboembolism?

• Mayo Clinic - Pulmonary embolism

• National Library of Medicine - Virchow Triad

• Atrial fibrillation

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