What kinds of blood clot complications can occur?

What kinds of blood clot complications can occur?

Thrombi which form in small, superficial veins are not normally considered dangerous as these are not normally responsible for transporting clots to vital organs, such as the lungs or heart. A thrombus in the arterial or deep veins are normally more a cause for concern, especially if it is mobile.

 Anatomy of deep vein thrombosis.

Potential health problems and complications of blood clots include:

  • Deep vein thrombosis (DVT): A clot which does not embolise (travel elsewhere in the body) can cause considerable local pain and swelling to an affected portion of the body (e.g. a leg). Blood is restricted from travelling back to the heart and thus causes associated symptoms depending on the location on the thrombus. A piece of a blood clot can, however, break loose and embolise, travelling to another portion of the body and result in serious complications, such as a pulmonary embolism.
  • Pulmonary embolism (PE): This is considered a potentially life-threatening condition and must be attended to by a medical professional urgently. A clot in the lungs that becomes lodged in the pulmonary artery is known as an embolus / travelling clot and often originates from those that developed in the arm or leg. Serious illness, long-term damage or death can occur as a result of severely reduced lung function due to compromised blood supply and blockage (hypoxia – severe reduction of oxygen). Damage can extend to other organs of the body including the heart.
  • Arterial thrombus: A blood clot that travels through the main arteries causes blood to pool and forms a blockage which restricts blood supply (including nutrients and oxygen) to all cells and the tissues beyond it. This can rapidly cause tissue death, and result in serious complications such as stroke (when a clot affects the brain), heart attack (when a clot develops in the arteries of the heart) (8), ischemic bowel or mesenteric ischemia (due to a clot in the intestine), and peripheral vascular disease (due to a clot in one of the legs).
  • Kidney failure: Blood clots which reach the kidneys can cause extensive damage and ultimately result in kidney failure. Clots cause a blockage which leads to a reduction in arterial blood flow to the kidney and therefore a reduction in kidney function. This leads to an accumulation of waste and fluids, which would normally be expelled from the body, as well as elevated blood pressure levels (hypertension).
  • Pregnancy complications: Pregnancy related changes in the body (hormone production and pressures associated with a growing baby) raise a woman’s risk of developing blood clots. Those that do develop during pregnancy normally occur in the pelvis and lower extremities (legs). This then increases risk for pulmonary embolism, as well as pregnancy related complications – miscarriage, premature labour or maternal death.


8. US National Library of Medicine - National Institutes of Health. January - March 2013. Arterial embolism: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3665125/ [Accessed 28.08.2018]

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