Symptom Management, Palliative Care, or Supportive Care to relieve side-effects is an important part of cancer care and treatment and should always form part of the overall treatment plan.

Individuals with cancer, especially those undergoing treatment, are at risk for blood clots. Someone with a clotting disorder may get blood clots in the veins or arteries if the blood forms a clot inappropriately.

Normal blood clotting (coagulation) is a complex process in which specialised blood cells (platelets) and different proteins in the blood (clotting or coagulation factors) clump together to heal broken blood vessels and control bleeding. There is a delicate balance of coagulation factors that promote bleeding and those that promote clotting.


Blood clotting disorders occur when some clotting factors are missing or damaged and form clots inside arteries or veins. These clots can block normal blood-flow and can break off and travel to other parts of the body, causing life-threatening problems.

When a blood clot occurs in a vein it is called a Deep Venous Thrombosis (DVT). If the blood clot occurs in a vein in the lungs, or travels into the lungs, it is called a Pulmonary Embolus (PE). A blood clot can also occur in an artery, which is less common but also very serious.

Individuals with cancer have a higher risk of blood clots and clotting disorders. This increased risk may be due to the cancer or treatments such as chemotherapy, surgery, steroids, or long-term use of a catheter. Long periods of inactivity, such as a long plane or car ride can also increase the risk of a blood clot.

Signs and Symptoms

Relieving side effects is an important part of total cancer care and treatment, which is why you should discuss any symptoms your child is experiencing, new symptoms and changes in symptoms with their Oncology Team so that they can work out a regimen of palliative or supportive care for them.

People with clotting problems may experience some of these symptoms:

  • Leg swelling on one side of the body
  • Low oxygen levels
  • Pain in the arm or leg where a blood clot is located
  • Rapid heart beat
  • Trouble breathing or chest pain when breathing

It is critical that you inform your child’s doctor about any blood clots immediately. Symptoms very often do not occur until the level of platelets is extremely low and patients often do not know they have a blood clot until it is diagnosed during a test.


A blood clot in the arms or legs is most commonly diagnosed using a type of ultrasound technique called a Doppler. This test uses sound waves to look at the flow of blood in veins. It can detect decreased blood flow from a blood clot.

A blood clot in the lungs (pulmonary embolism) is usually diagnosed with a computed tomography (CT) scan, in which special dye called a contrast is injected into a patient’s vein before the scan to provide better detail on the image and a three-dimensional picture of the inside of the body is created with a special x-ray machine

A test called a lung ventilation/perfusion, or VQ, scan is sometimes used to diagnose a blood clot in the lungs. This test consists of two different scans: the ventilation scan that looks at the airflow in the lungs and the perfusion scan that looks at the blood flow in the lungs.

A blood clot in an artery is generally diagnosed by an angiogram: a dye is injected into an artery, which is then examined with a special x-ray device called a fluoroscope.


A blood clot is life-threatening and needs immediate treatment.

The most common treatment for blood clots is to administer blood thinners, either by injection under the skin or into a vein. Once the blood is considered thin enough, so that there I no longer a risk of clotting, the patient may be given a blood thinner as a pill that is swallowed. Patients who are given blood thinners must be regularly monitored to ensure that there is no increased bleeding.

Some patients cannot be given blood thinners because their platelet levels are too low, or they have a high risk of bleeding. In these cases, a special type of filter can be placed in the body to prevent a blood clot from traveling to the lungs where it can be very dangerous.