Understanding the causes of blood clots

Health A-Z

Blood clots essentially refer to coagulated blood with a gel-like structure. Blood clots are formed to stop bleeding from an injury. Once the bleeding from the wound stops, the role of the blood clot ends. Clots that persist even after the tissue heals often end up in your veins or arteries or just about any part of your body.

Blood clots present in blood vessels hinder blood flow to vital organs like the lungs, heart, or brain, which can lead to life-threatening situations. Excessive blood clotting or hypercoagulability is another complication of blood clots. Hypercoagulability results in too many blood clots or blood clots that do not dissolve fully. Depending on where in the body it occurs, clotting can cause tender and swollen limbs, chest pain, dizziness, abdominal pain, palpitation, or even coughing of blood if the clot is in the lungs. Here is a look at the major causes of blood clots.

Clotting at the site of an injury
Blood clots are formed whenever the flowing blood comes in contact with specific chemicals in the skin or walls of blood vessels. Blood clots are composed of platelets and fibrin. Platelets are generated in the bone marrow. When bleeding occurs, platelets stick to each other. Fibrin resembles long, sticky strings that stick to the walls of the blood vessels and also clump together. Fibrin and platelets together form a web-like structure to tighten the clot that helps the underlying tissue to heal in a better way.

Clotting in unwanted locations
Waxy cholesterol plaques that are formed in the arteries contain chemicals that cause clotting. Clotting inside the arteries occurs when this plaque breaks open. Majority of heart attacks or strokes happen when the plaque in the heart or brain bursts open suddenly. Blood clots are also formed when the blood does not flow properly, resulting in pooling of blood in the vessels. Pooling of blood causes platelets to stick together. Arteries narrow down as they move away from the heart, so a clot that starts near the heart moves into a narrower blood vessel. This results in the blockage of blood supply, which causes the organ to starve for oxygenated blood. Veins, however, tend to widen as they near the heart, so the clots in the veins travel to the heart and get pumped into the lungs, resulting in a life-threatening condition known as pulmonary embolism.

The following factors and conditions can cause troublesome blood clots:

  • Deep vein thrombosis
  • Antiphospholipid syndrome
  • Heart arrhythmias
  • Heart attack
  • Stroke
  • Pregnancy complications
  • Smoking
  • Obesity
  • Prolonged sitting or bed rest

Prescription medication is given to prevent excessive clotting and thinning of blood in most cases. Some medicines prevent platelets from binding together. Blood-thinning medications control the formation of clots.

The role of blood in the human body is quite a tricky one—it must maintain a continuous flow throughout the body, but quickly seal off a leak due to an injury by forming blood clots. Blood clots are essential to stop bleeding from a wound; however, at the same time, it can cause serious medical issues when formed in unwanted places.