What is an air embolism?

An air embolism is an air bubble that enters your arteries or veins and is usually a complication of a medical procedure.

As these bubbles move, they can block the blood supply to different parts of the body, such as the heart, lungs or brain. This can lead to serious problems, such as a stroke.

Fortunately, air embolisms are very rare. In this article, you’ll learn about some of the different types of air embolisms and their potential causes. You will also learn about symptoms, diagnosis and treatment.

Different Types of Air Embolism

Generally, an embolism is a foreign body that travels in the blood and blocks a blood vessel. If the type of embolism is not specified, a thrombus is assumed to be the cause, such as pulmonary embolism. Air embolisms are much less common than blood clots.

An air embolism that occurs in a vein is called a venous air embolism. If you have an air embolism in your arteries, you have an arterial air embolism.

Arterial air embolism is usually more dangerous than venous air embolism. In some people, a venous embolism can enter the arterial system and become a venous air embolism.

An air embolism is also sometimes named after the location where it caused the problem. For example, when these air bubbles are in your brain, they are called cerebral air embolisms.

air embolism symptoms

Small air embolisms usually cause no symptoms at all. Many of these air emboli may never be detected, and they will eventually go away on their own.

But when they do cause problems, the results can be serious. The type and severity of symptoms depend on the size and number of air embolisms, as well as their location in the body.

When symptoms do appear, they tend to come on suddenly. Potential symptoms may include:

  • shortness of breath
  • persistent cough
  • chest pain
  • Seizures
  • headache
  • loss of consciousness
  • change of mind
  • Muscle weakness or paralysis on one side of the body
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Get medical help right away if you experience any of these symptoms after a medical procedure. If you are undergoing a medical procedure and start noticing these signs, speak up right away.

In severe cases, when the heart cannot pump enough blood, an air embolism can cause a person to die quickly from cardiac arrest.

Causes of air embolism

Air embolisms cause symptoms as they pass through a person’s blood vessels. When they get stuck (because the blood vessels are so small), they block blood flow to the area.

Most of the time, air embolisms occur as a result of rare complications during medical procedures and surgery. The most common occurrence is an air embolism during centerline placement. This is a thin tube inserted into a large vein in the neck, chest, groin, or upper arm to deliver medicines or fluids.

However, embolism can occur in many other procedures involving blood vessels. Examples are:

  • Angiography (imaging using dyes and X-rays to better see blood vessels)
  • Tissue biopsy (taking a sample of tissue, such as lung tissue, for diagnostic purposes)
  • Hemodialysis (removal of waste, salt, and fluids from the blood for people with severe kidney disease)
  • Endoscopic retrograde cholangiopancreatography, or ERCP (a procedure to diagnose and treat problems with the gallbladder, liver, and pancreas)
  • Surgery (such as brain surgery, heart surgery, or hip surgery)

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The following conditions can also, but rarely, cause an air embolism:

  • physical trauma
  • deep dive
  • on a ventilator
  • childbirth (amniotic fluid embolism)

Diagnosis: Early recognition is key

During diagnosis, your healthcare provider learns about the entire clinical situation, including a person’s symptoms, their tests, and their other medical conditions.

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The key to diagnosing an air embolism is timing. Symptoms of an air embolism can begin during a medical procedure by accidentally letting excess air into your veins or arteries. Or they might start shortly after (a day or so, but usually earlier).

Sometimes, imaging used in medical procedures can help locate abnormalities. For example, CT imaging (computed tomography) used for lung biopsies can provide images of emboli.

The same image might be able to show that air is where it shouldn’t be. In other cases, other types of medical imaging, such as angiography, may be used to show air in veins or arteries.

It is important to diagnose an air embolism quickly so that appropriate treatment can be obtained as soon as possible. This will greatly reduce the chance of major complications or death.

How is an air embolism treated?

If the procedure that caused the embolism is still in progress, the first step is to stop it and not allow more air to come in.

Patients also often need to be repositioned so that they lie on their left side with their feet elevated and their head lowered. In this location, air embolisms are less likely to spread to the brain and heart, where they can cause the greatest danger.

The bubble will slowly dissolve on its own, but clinicians can take steps to help it dissipate more quickly. For example, the patient is also given extra oxygen to breathe, which helps reduce the size of air emboli and reduces tissue damage.

If available, the person may also be treated in something called a hyperbaric chamber. This is especially important for people with very severe symptoms.

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What is a hyperbaric oxygen chamber?

In this treatment, the individual enters a tubular chamber where the patient is inhaled with 100% oxygen in a pressurized environment. This allows more oxygen to enter your body and causes the air embolism to shrink in size faster.

Prognosis: What can I expect?

The prognosis of air embolism varies widely. In some people, symptoms go away with prompt recognition and treatment. But a lot depends on the type of air embolism you have.

In recent years, the use of hyperbaric oxygen has improved outcomes for many people. Unfortunately, some people have lingering symptoms, such as some weakness on one side of the body, even after the air embolism clears. Some people do die from them.

For people with air embolisms into the brain, one study found that 21 percent of those who received hyperbaric oxygen died within a year. Six months after the event, 75 percent of survivors had little or no remaining disability.


Air embolism is a very rare but potentially life-threatening complication that can occur during surgery and medical procedures. An air embolism can cause symptoms as it passes through a person’s blood vessels, such as blocking blood flow to the area. It requires immediate diagnosis and treatment, possibly with hyperbaric oxygen. Prognosis varies widely.

VigorTip words

Air embolism can be a devastating and unexpected complication of medical procedures. Fortunately, this is very rare and probably not worth worrying about in advance. The benefits of the necessary medical procedures may far outweigh the small risk of developing an air embolism.

Still, if you suspect a problem, being aware of this rare possibility may help you seek immediate medical attention.

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