Blood clots: an overview and more

A blood clot, also called a thrombus, is clotted or clotted blood. Although blood clotting is essential in some circumstances, for example to heal a skin wound by crusting, blood clots that develop in arteries or veins can be dangerous and even life-threatening if they block the bloodstream. blood flow to important organs, including the heart. , lungs and brain.

Get Medical Information / Emily Roberts

Symptoms of blood clots

The signs and symptoms of a blood clot depend on whether the clot is in an artery or vein and in which body it is found. For example, a clot in an artery can cause moderate to severe pain that develops quickly. If there is an affected vein, the pain is likely to be weaker and worse over several hours or even days.

Any blood clot can cause swelling, tingling, pain, or warmth.

If an artery in the brain is blocked, neurological symptoms such as confusion or paralysis can occur, which could indicate a stroke. A blood clot in your leg can cause leg swelling that is noticeably larger than the other leg and can be a sign of DVT. If a blood clot forms in a coronary artery, symptoms of a heart attack may appear, including tightness in the chest or arms and dizziness .


All injuries cause blood vessel damage. Bruising occurs when a blood vessel is damaged, causing blood to leak and become visible under the skin. Then a clot forms inside the blood vessel; Without this process, minor injuries can lead to uncontrolled bleeding.

Blood clots are made up of two elements: platelets and fibrin. Platelets are cells produced by the bone marrow that travel through the bloodstream. When bleeding occurs, platelets become sticky, allowing them to adhere to each other and to the walls of blood vessels.

Fibrin is a substance that resembles a long, sticky thread. Fibrin strands adhere to the walls of blood vessels and clump together to form a cobweb-like complex that red blood cells enter. A blood clot is made up of platelets and fibrin filaments, as well as trapped red blood cells. Fibrin strands bind platelets together and essentially squeeze the clot, making it stable .

The clotting mechanism can also cause clotting in harmful ways , a condition called thrombosis.

If a blood clot blocks an artery to the heart, the result can be a heart attack . If blood to the brain is blocked, a stroke can occur.

The arteries get smaller and smaller as they move away from the heart, so a clot that starts near the heart eventually settles into a smaller vessel. This prevents oxygenated blood from reaching the areas fed by this artery. Embolic strokes, for example, the most common type of stroke , are caused by the movement of blood clots into the brain and the depletion of blood and oxygen in brain tissue.

On the other hand, veins enlarge as they return blood to the heart, so blood clots that form in the veins can travel to the heart and then be pumped to the lungs, where they can create a life-threatening condition called pulmonary . . embolism . They can also get stuck in blood vessels, most commonly in the legs; When this happens, it is called deep vein thrombosis (DVT).

There are many risk factors that can predispose to the development of a potentially dangerous blood clot, including :

  • Atrial fibrillation is a condition that causes an irregular heartbeat.
  • Atherosclerosis, a build-up of plaque in the arteries.
  • Certain genetic disorders, such as the factor V Leiden (FVL) mutation
  • Certain medications, such as oral contraceptives and hormone therapy medications.
  • Cardiac arrhythmias (heart rhythm problems)
  • Heart failure
  • Obesity
  • Peripheral artery disease
  • The pregnancy
  • Sitting or bed rest for a long time
  • Of smoking
  • Operation


Various diagnostic tests are used to detect blood clots, based on your symptoms and the likely location of the clot. They include:

  • D-dimer blood test: measures the content of a substance in the blood, which can determine if there is abnormal blood clotting activity somewhere in the bloodstream.
  • Cardiac biomarker blood test: This is a blood test that can detect damage to the heart muscle and is used to diagnose a heart attack.
  • Compression ultrasound: This is a non-invasive test that can be performed at the bedside and is often very helpful in diagnosing DVT.
  • V / Q scan: A ventilation perfusion scan (V / Q scan) uses a radioactive dye to examine blood flow in the lungs and can determine if a pulmonary blood vessel is blocked by a pulmonary embolism.
  • CT: This is usually the first test used to diagnose a stroke. It is also helpful in confirming a pulmonary embolism.
  • MRI: MRI can be used to detect clots in blood vessels.
  • Angiography or venography: these are catheterization techniques in which a dye is injected into a blood vessel where a clot is suspected; X-rays are then taken to look for the clot.
  • Echocardiography Echocardiograms use sound waves to take pictures of your heart and are often used in patients who have had an arterial embolism, especially in people who have had an embolic stroke. To enter an artery, in almost all cases, an embolism must occur within the heart or pass through the heart.

Watch out

Prescription medications are the mainstay for preventing and treating blood clots , although some people may need surgery. Medications used to treat blood clots include :

  • Anticoagulant drugs: inhibit one or more blood clotting factors, a group of blood proteins responsible for blood clotting.
  • Antiplatelet drugs: These drugs are used to reduce the "stickiness" of platelets, the tiny blood cells that make up the nucleus of a blood clot. By inhibiting the ability of platelets to bind together, these drugs inhibit blood clotting.
  • Thrombolytic drugs: These powerful drugs, also known as fibrinolytic agents or "blood clot busters," are given intravenously to dissolve blood clots that are forming. For the most part, its use is limited to patients in the first hours after an acute heart attack or stroke in an attempt to reopen a blocked artery and prevent permanent tissue damage.


Several of the strategies to prevent blood clots are recommended for overall health and wellness.

Get regular exercise, maintain a healthy weight, and avoid smoking. This last recommendation is especially important when it comes to blood clots, as they can cause inflammation that can lead to thrombosis.

Make sure all of your chronic health conditions, especially cardiovascular disease, are properly managed and, as much as possible, avoid sitting for long periods of time.

Get the word of drug information

Blood clots can be dangerous, so if you experience any symptoms that you think might indicate a clot, call your doctor immediately or go to the emergency room. Fortunately, there are many medications that can effectively prevent and treat blood clots.

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