Blood Clots and Their Evaluation, Treatment and Prevention
What is 'Thrombosis'?
Thrombosis is a word for a blood clot that occurs in an unwanted site.
Thrombosis can occur in the veins (deep vein thrombosis, superficial vein thrombosis), and can occasionally break off and travel to the lungs (pulmonary embolus). Blood clots can also occur in arteries causing conditions such as myocardial infarction (heart attack), stroke, and other rarer conditions such as lower limb ischaemia (poor blood supply) and retinal infarcts causing visual loss.
Why does Thrombosis occur?
Unwanted blood clots can be due to underlying conditions that make your blood prone to clotting. Situations that can contribute to clotting risk include older age, obesity, smoking, serious medical illness, surgery, trauma, oestrogen and other hormones (via the birth control pill, hormone replacement therapy or pregnancy), immobility (such as long haul travel), and some inherited or acquired disorders of clotting referred to as 'thrombophilias'.
What are the symptoms of a clot?
Leg vein clots in the deep veins (DVT) can cause pain, swelling, discolouration and heat in the affected leg. They can also have no symptoms at all.
Leg vein clots in the superficial veins (Superficial Vein Thrombosis) can cause pain and tenderness over a superficial (surface) leg vein, and the vein can feel hardened, like a cord.
Pulmonary embolus can cause shortness of breath, pain or discomfort in the chest, back or shoulders, cough and sometimes blood stained sputum. Occasionally they can cause collapse and loss of consciousness. They can rarely have no symptoms at all.
Arterial clots such as heart attacks can cause chest pain, shortness of breath, collapse. Strokes can cause loss of function of the limbs, or alterations in consciousness, speech, vision, or balance.
How are blood clots diagnosed?
Your doctor will take a family history, full medical history and examination, and then order some tests. Blood clots are investigated using blood tests, ultrasounds and other scans to assess the site of the clot, and special blood tests may be ordered to try to define the underlying cause of the clot.
How are blood clots treated?
Your doctor will prescribe blood thinning medications to stop the clot getting any bigger, prevent the clot from moving to other sites, and reduce the chance of long term complications. You will be counselled on what caused your clot, how to prevent clots in the future, how long you need to be treated for and what other tests you may need.
To learn more, see our patient information sheet on DVT and Pulmonary Embolus, and for more information on inherited and acquired disorders of clotting, click here.