Thrombosis: symptoms, causes and treatment

Thrombosis is a condition in which the blood clots too easily. The blood clots that may form, so-called thrombuses, can block the blood vessels and cause a lack of oxygen in the tissue in question. This can lead to a thrombosis, but also to a stroke or heart attack. When an embolus, a piece of detached tissue from the thrombus, occludes a blood vessel, it is called an embolism.

  • What is thrombosis?
  • Symptoms of thrombosis
  • Thrombosis, how do you get it?
  • Thrombosis, how do you get rid of it?


What is thrombosis?

Thrombosis is a condition in which the blood clots too easily, causing blood clots to form in the blood vessels. Blood clotting is a complicated process that ensures that smaller and larger bleedings in the body stop quickly. Small hemorrhages regularly occur in the blood vessel system, which are quickly stopped thanks to the blood clotting process. Bleeding on the outside of the body, such as a cut on your finger, also generally stops fairly quickly. In people with thrombosis, the blood clotting process is disrupted, causing the blood to clot too easily . This can cause so-called thrombuses , clots in the blood vessels. In most cases you will not notice these clots at all and they will be broken down by the body. However, the blood clots can also be so large that they can close off part of a blood vessel and thus limit the oxygen supply. A so-called infarction then occurs.
A distinction is often made between two types of thrombosis, depending on the location of the thrombosis:

  1. Arterial thrombosis: thrombosis of the artery
  2. Venous thrombosis: thrombosis in the veins



In some cases, a piece of the thrombus breaks off, this is called an embolus . The detached blood clot moves with the blood flow. When an embolus enters a blood vessel and occludes this blood vessel, it is called an embolism. Myocardial infarction and stroke can result from an arterial thrombus, a pulmonary embolism from a venous thrombus.

Symptoms of thrombosis

Thrombosis does not always immediately cause characteristic symptoms and is partly dependent on the consequences of the thrombosis. The symptoms of two serious possible consequences of arterial thrombosis – myocardial infarction and stroke – are described below.

Heart attack

People with a heart attack often experience oppressive or oppressive chest pain, which can radiate to the arms, back or jaw. The pain is usually severe, but fairly constant, without sharp stabbing pains. Other additional symptoms of a heart attack are nausea and sweating. A myocardial infarction in women and the elderly often presents a less characteristic picture, which means that the myocardial infarction is not always recognized as such.


A stroke can be characterized by, among other things, symptoms of loss or paralysis on one side of the body, extreme headaches, sudden problems with speaking or seeing and loss of strength in the arms or legs. The so-called FAST test is a way to recognize a stroke. The FAST test consists of the following steps:

  • F (face): ask the person to smile. A crooked mouth or drooping corner of the mouth can indicate a stroke.
  • A (arm): Have the person lift both arms and extend them in front of them, with the inside of the hand facing up. Sagging or wandering arms may indicate a stroke.
  • S (speech): ask the person and/or bystanders whether there has been a change in speech, as this may indicate a stroke.
  • T (time): try to find out how long these symptoms have been occurring, this is important information for emergency services.


Venous thrombosis and pulmonary embolism

The symptoms of venous thrombosis are not always clear. A common form of venous thrombosis is thrombosis in the leg, the so-called thrombosis leg . In typical cases of a thrombosed leg, there is an acute, painful and thick leg, which is blue-red in color and warmer than the other leg. Chest pain, difficulty breathing, shortness of breath and coughing up bloody mucus may indicate a pulmonary embolism. Additional imaging tests are often used to diagnose venous thrombosis and pulmonary embolism.

Thrombosis, how do you get it?

Cause arterial thrombosis

Atherosclerosis often plays an important role in arterial thrombosis . Atherosclerosis is a condition in which the inner layer of the blood vessel wall is thickened by an accumulation of fatty substance and calcium deposits. Thrombosis can form on top of this. Risk factors for developing atherosclerosis include:

  • Too high blood pressure
  • Too high cholesterol
  • Diabetes mellitus
  • Smoking


Cause venous thrombosis

Virchow, the cause of venous thrombosis often falls into one of the three categories below, also called the ‘ Wilchow triad ‘:

  1. Altered clotting ability of the blood
  2. Altered blood flow
  3. Altered vessel wall

Increased clotting ability of the blood can occur when there is a deficiency of certain inhibitors of blood clotting, such as antithrombin III or protein C. Altered blood flow can occur when you take a long plane trip or car ride, or are confined to your bed for a while. for example, in the event of a hospital admission. During pregnancy and the postpartum period, the above risk factors are combined: there is temporarily increased clotting ability and reduced mobility (and therefore reduced blood flow). Vascular wall abnormalities, such as is the case with atherosclerosis, can also increase the risk of thrombosis . Finally, certain contraceptive pills can also increase the risk of thrombosis. The so-called second-generation pills (combined contraceptive pills with levonorgestrel or noretisterone) appear to have relatively the least risk of thrombosis and are therefore often considered the first-choice contraceptive pill.

Thrombosis, how do you get rid of it?

What can you do yourself?

Ensure a healthy and varied diet and have your blood pressure and cholesterol levels checked regularly. Furthermore, make sure that you do not sit or lie in the same position for too long: take regular short walking breaks during long journeys, take a walk in the aisle of the plane and move your legs regularly when you are bedridden. And lastly: exercise enough.

What can the doctor do?

During hospital admissions and after operations, blood-thinning injections are usually administered to slightly inhibit blood clotting. After certain operations you must take certain blood-thinning medications for a longer period of time. If you are known to have thrombosis, you will receive blood-thinning injections and/or blood thinners , which you sometimes have to continue taking. You should also have regular check-ups at the thrombosis service .

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