An embolism is the sudden obstruction of a blood vessel by a blockage-causing piece of material called an embolus.


An embolism is the sudden obstruction of a blood vessel by a blockage-causing piece of material called an embolus. The blockage is often caused by a blood clot (thromboembolus). The embolus may also be a fat globule, amniotic fluid, tumour tissue or bubble of air. Symptoms vary according to the location of the obstruction. An embolism is an emergency.


Depending on the location and type of embolism

Causes and treatment


Sudden partial or total blocking of a blood vessel by a piece of material travelling in the blood stream (known as an embolus)

  • Thromboembolism (dislodged embolus)Venous embolism
    • The blood clot usually forms in the leg (deep leg vein thrombosis)
    • Moves from the place of formation towards the lungs
    • Blockage of one or more arteries in the lungs (pulmonary or lung embolism)
    Arterial embolism
  • Fat embolism (fat globule from fat tissue)
    • Accidents
    • Operations
  • Bone marrow embolism (pieces of bone marrow)
  • Amniotic fluid embolism (amniotic fluid floods into the mother’s pulmonary artery)
    • Delivery/birth
    • Caesarian section
  • Air or gas embolism (bubbles of gas or air in the bloodstream)
    • Decompression sickness
  • Tumour embolism (tumour fragments in the bloodstream)
Risk factors

Further treatment by your doctor / in hospital

Possible tests
  • Physical examination
  • Neurological examination
  • Blood test
  • Arterial ultrasound
  • X-ray, CT or MRI imaging of arteries (angiography)
Possible therapies
  • Removal of embolus
    • Medication to dissolve the embolus
    • Catheter-directed dissolution, mechanical
    • Operation
  • After a thromboembolism: patient has to take blood thinners (often for life)
  • Treat underlying disease

What can I do myself?

  • During long trips
    • Take breaks to stretch the legs
    • Leg exercises (e.g. rotate/lift the feet, tense/relax calf muscles)
    • Support stockings, if necessary
  • Healthy lifestyle, avoid risk factors
    • Diet, normal weight
    • Stop smoking
    • Avoid stress; relaxation
    • Avoid inactivity; get regular exercise

When to see a doctor?

Symptoms of an embolism should be treated as an emergency (emergency number 144)

  • Acute, severe pain (leg, arm, chest/heart, stomach)
  • Breathing difficulties
  • Leg or arm is cold and pale
  • Leg is swollen and red
  • Problems/symptoms while/after sitting down (e.g. while travelling) or lying down for a long time
  • Sagging facial muscles, limp arm, slurred speech (typically one-sided)


embolism, embolus, thromboembolism, fat embolism, tumour embolism

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