The online Community for people with spinal cord injury, their relatives and friends


What is thrombosis and what causes it?
Thrombosis is a condition where a blood clot (thrombus) forms inside a blood vessel and thus causes a restriction or blockage of the blood flow within the vessel. Thromboses are dangerous as they might lead to a pulmonary embolism (see FAQs) in case the blood clot travels to the lungs.

Causes of thrombosis (Source: Kliniken des Main-Taunus-Kreises GmbH)
Causes of thrombosis (Source: Kliniken des Main-Taunus-Kreises GmbH)

What causes thrombosis?

  • Blood flows slowly when sitting for long periods of time, lack of muscle activity in the legs, confinement to bed, injuries such as bone fractures etc. – therefore increased risk in people with spinal cord injury
  • Increased risk in people who: are overweight, smoke, have already had thrombosis or use certain medication (e.g. birth control pill)

What are the signs and symptoms of thrombosis?
Possible physical trouble:

  • Sudden pain in the affected area
  • plantar pain
  • dragging pain along the vein
  • In case of no sensation of pain, symptoms may include:
  • one leg is significantly thicker than the other
  • redness of skin and warm skin in the affected area
  • Increased frequency of spasms and spasticity
  • Heavy legs/feeling of tension in the legs
  • General feeling of discomfort
  • Rapid pulse, slightly elevated body temperature, shortness of breath
Legs with and without thrombosis (Source: Kliniken des Main-Taunus-Kreises GmbH)
Legs with and without thrombosis (Source: Kliniken des Main-Taunus-Kreises GmbH)

How to prevent thrombosis:

  • sufficient fluid intake (see FAQs)
  • wearing of compression stockings in case of extensive swelling of the legs
  • injection of blood-thinning preparations in case mobilisation is restricted for a certain period of time => please contact physician

When do I have to be especially careful?

  • warmer temperatures: sufficient fluid intake
  • when traveling
  • hot climate: sufficient fluid intake
  • on journeys shorter than four hours: possibly wear compression stockings
  • on journeys longer than four hours: injection of blood-thinning preparations => please contact physician
  • in case of leg injuries, e.g. fractures or heavy bruises as a result of a fall => please contact physician
  • in case of infections => please contact physician


Thrombosis has to be treated as soon as possible as the results can be life threatening.
In case a thrombosis is suspected, the GP must be contacted immediately. It is important to move as little as possible (e.g. mobilisation) – the thrombus might be released and cause a pulmonary embolism.



What kind of compression stockings do I need?
Compression class 2. To be effective, the compression stockings must fit well. In case you already have older stockings at home, make sure they still fit and are effective.

What is a pulmonary embolism?
A pulmonary embolism is a life threatening condition caused by a sudden blockage of a blood vessel in the lungs. E.g. the vessel might be blocked by a blood clot that originated in the leg. Symptoms of a pulmonary embolism include: shortness of breath, anxiety, irritation of the throat, rapid pulse.

What does sufficient fluid intake mean?
It is recommended to drink 2.5 liters each day – on hot days correspondingly more. 1.5 liters of urine have to be excreted through the bladder each day. Suitable fluids are water and fluids that are rich in minerals (mineral water).


About the author:

  • Christa Schwager is a specialist in movement science in the Department for Nursing Development and Education at the Swiss Paraplegic Centre in Nottwil/Switzerland, where she has worked since 1994. She is co-author of the key publications in the field of spinal cord injury "Paraplegie. Ganzheitliche Rehabilitation" (eds. Guido A. Zäch & Hans Georg Koch) and "Pflege von Menschen mit Querschnittlähmung" (ed. Ute Haas).

updated: December 2013