Difference Between Thrombosis and Embolism (With Table)

An integral job of the blood vessels is to supply blood to the different parts of the human body. There are various kinds of vessels that help perform this activity. Arteries and veins are two of the most common example of vessels that transfer blood towards and beginning from the heart. The blood comprises of plasma, platelets, white blood cells and red blood cells.

In a normal scenario, it is easy for blood to flow all the way via the arteries and veins. But in certain cases, if there is any kind of injury in the intima of the blood vessel, certain difficult mechanisms start taking place inside the bloodstream. This is done to create a clot. A clot is basically produced due to the opening of thrombocytes in blood. 

A blood clot needs fibrin to be created. Fibrin forms the net on the clot. The process of formation of a clot in a blood vessel is either known as Thrombosis or Embolism. Though it appears that these two words are the same, they are not. Both of these are in actuality quite different from each other.

Thrombosis vs Embolism

The difference between Thrombosis and Embolism is that Thrombosis is when the flow of blood is blocked because of the production of a blood clot within a blood vessel. On the other hand, Embolism is when either the entire blood clot or a part of the blood clot is separated from its actual place, causing an occlusion at another body part. 

Comparison Table Between Thrombosis and Embolism  

Parameter of ComparisonThrombosisEmbolism 
Meaning Thrombosis is when a blood clot originates in a blood vessel, leading to the blockage in the flow of blood.  Embolism is when a blood clot (either full or part of it) is separated from its place leading to occlusion at another body part.
FormationIn Thrombosis a blood clot is formed in a vein.In Embolism, a clot moves through the blood vessels before reaching a smaller vessel. 
Blood flowIn Thrombosis the blood flow is reduced.In Embolism, the blood flow is completely shut off.
Symptoms The symptoms of Thrombosis are warm or cold skin in the area of pain and cramps in the leg. The symptoms of Embolism are rapid heartbeat, discoloured skin and dizziness. 
SizeA Thrombosis is large in size.An Embolism is smaller as it is a piece of the Thrombosis. 
CausesA Thrombosis is caused due to blood platelets, fibrin and other such cellular elements. An Embolism is caused due to Thrombosis mostly. In certain cases, it may be caused due to air infections.
Mass In Thrombosis the mass is stationary. In Embolism, the mass is freely floating.

What is Thrombosis?

Thrombosis refers to the formation of blood clots in areas where blood clots are not medically needed. In a case, where a body is injured in any way, the blood clots at the injury so that there isn’t much blood loss and the injured area can be healed faster. This is done to protect the affected area. 

However, in certain cases, blood clots are formed in blood vessels, without any need. This is either because the speed of the blood flow changes or the core content of blood changes. This is what Thrombosis is all about. Thrombosis affects the flow of the blood in the body. Because of the clots, the blood vessels can be half or full blocked, which prevents the normal circulation of blood. 

Thrombosis is more common among people who cannot move freely for any reasons. People who have a sedentary lifestyle are more prone to Thrombosis. Thrombosis is often called the
“economy class syndrome”. This is because the growth of deep vein thrombosis is often associated with air travel. Other factors like drinking, smoking or obesity also determine Thrombosis in a human body. 

What is Embolism?

Embolism basically refers to a blood vessel that has been blocked. Blood clots tend to block blood vessels partially or completely, leading to Embolism. Other causes of Embolism include gas bubbles, air bubbles or the entrance of any foreign substances into the bloodstream. In certain rare cases, embolisms are created artificially to reduce the flow of blood to a cancerous tumour.

The symptoms of Embolism depend on the area of the blockage. Clots are able to block vessels, which causes the abnormal circulation of the blood in the body. In cases, when Embolism blocks veins, blood starts to build up behind the blockage leading to swelling.

Main Differences Between Thrombosis and Embolism

  1. In Thrombosis a blood clot is originated in a blood vessel, which blocks the flow of the blood. On the other hand, in Embolism either the entire blood clot or a part of the blood clot is separated from its actual place, leading to occlusion at another body part. 
  2. Thrombosis lasts for several days or horse while on the other hand, Embolism lasts for several minutes.
  3. The symptoms of Thrombosis are less severe and less dramatic while on the other hand the symptoms of Embolism are more severe and more dramatic.
  4. In Thrombosis the blood flow reduces, while on the other hand, in Embolism the blood flow completely stops.
  5. A Thrombosis is bigger in size whereas, on the other hand, an Embolism is smaller in size.
  6. In Thrombosis a blood clot develops inside the circulatory system while on the other hand in Embolism a blood clot travels through the blood vessels.


In normal day-to-day activities, blood vessels supply blood to the various body parts of the human body. Arteries are veins are among the various blood vessels that help to transfer blood to the other body parts from the heart. 

When in a blood vessel a blot clot is formed it leads to the blockage in the flow of blood. This is termed as Thrombosis. On the other hand, when a blood clot, either partially or fully is separated from its actual place, leading to occlusion at another part of the body, it is termed as Embolism. 


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2539330/
  2. https://academic.oup.com/ajhp/article-abstract/63/20_Supplement_6/S5/5134711