What Is Embolism? What Are The Different Types Of Embolism?

Editor's Choice
Main Category: Cardiovascular / Cardiology
Also Included In: Blood / Hematology;  Vascular;  Respiratory / Asthma
Article Date: 12 Jun 2009 - 2:00 PDT

email to a friend   printer friendly   view / write opinions   rate article

An embolism - from the Greek émbolos meaning "stopper" or "plug" - is the term that describes a condition where an object called an embolus is created in one part of the body, circulates throughout the body, and then blocks blood flowing through a vessel in another part of the body. Emboli (plural of embolus) are not to be confused with thrombi (plural of thrombus), which are clots that are formed and remain in one area of the body without being carried throughout the bloodstream.

What are different types of embolism?

Though most people are familiar with the term pulmonary embolism, describing an embolus that clots an artery carrying blood to the lungs, there are several other types of embolism. These include:

• Brain embolism - a clot that can prevent blood flow to the brain and can cause an ischemic stroke


• Retinal embolism - small clots that can block blood flow to the retina of the eye and can cause sudden blindness in an eye


• Amniotic embolism - amniotic fluid during pregnancy that can form clots and reach the lungs, resulting in pulmonary amniotic embolism


• Air embolism - air bubbles that form clots in the arteries and block blood flow, often seen in SCUBA divers who rise to the surface too quickly


• Thromboembolism - a blood clot (thrombus) that breaks free to form an embolus, capable of causing a heart attack


• Cholesterol embolism - cholesterol from plaques in a blood vessel break free and form a blockage


• Fat embolism - fat droplets enter the blood stream and block blood flow, usually a side-effect of certain surgeries or bone fractures


• Septic embolism - embolism infected with bacteria containing pus


• Foreign body embolism - any other small particle or object that enters the circulatory system and manages to block the flow of blood.

Who is at risk of developing an embolism?

Any person who has a condition that increases the risk of blood clots also has a higher risk of embolism. For example, heart diseases, blood abnormalities, HIV, trauma to legs, cancer, infections, and menopause increase the risk of embolism by making people more likely to develop blood clots. Elderly persons, obese people, and pregnant women may also be more likely to develop emboli.

Long periods of immobilziation put strain on the circulatory system. Blood clots are more likley to occur in people who have remained in one position during long plane or car trips and those who are assigned to bed rest after illness or surgery.

SCUBA divers who rise to the surface too quickly are likely to develop a condition called "The Bends", which is a type of gas embolism.

What are the symptoms of embolism?

Symptoms of embolism vary from barely noticeable to full-blown heart attack and greatly depend on the type and size of embolism.

An embolism such as a thromboembolism that blocks blood flowing through a coronary artery on the surface of the heart may cause a heart attack (myocardial infarction) as a symptom. Cerebral (brain) emboli are likely to lead to transient ischemic attack (TIA) or stroke, symptoms of which include weakness or tingling on one side of the body, confusion, speech problems, vertigo and balance problems, difficulty with vision, and severe headache.

When emboli block blood flow to a particular organ, symptoms tend to be local to the area of the body or the extremity that is deprived of flowing blood. It is common for emboli to cause pain, numbness, coldness, tingling, no pulse below the blockage, skin marks, increased skin sensitivity, and muscle spasm or paralysis. As the tissue dies, blisters and gangrene may result.

Pulmonary embolisms, usually resulting from a deep vein thrombus (DVT) that begins in the legs, breaks up, and travels to the pulmonary arteries, will result in chest pain, increased heart beat, dizziness, difficult catching breath, rapid breathing, and cough.

The other types of embolism may exhibit similar symptoms to those mentioned above. In addition, fat and cholesterol embolisms are known to form a skin condition called cyanosis, which is a bluish tint to the skin. Air emboli may also quickly lead to convulsions, cardiac arrest, and cardiac death.

How is an embolism diagnosed?

Diagnosis of embolisms depends on patient history, physical examinations, and a suspicion that a person's symptoms are due to an embolism. Tests that are frequently employed in order to diagnose embolism include:

• Electrocardiogram (EKG) - records the electrical activity of the heart


• Arterial blood gas study - measures oxygen, carbon dioxide, and other gases in the blood


• Chest x-rays - generates a picture of the heart, lungs, and other internal organs


• Pulmonary V/Q scan - two tests that analyze ventilation and structural properties of the lungs


• Computerized tomography (CT) scan (with and without contrast) - visualizes abnormalities in the chest, brain, etc.


• Pulmonary angiogram - visualizes blood clots in the lungs


• Ultrasound - high frequency sound waves that measure blood flow velocity and changes in blood flow


• D-dimer test - blood test that can diagnose thrombosis


• Electroencephalogram (EEG) - records electrical activity in the brain


• Magnetic resonance imaging (MRI) - uses magnetic waves to develop detailed pictures of the brain and other organs

How are embolisms treated?

Treatments for embolism depend on the size, location, and nature of the blockage. Survival increases if physicians can quickly determine the type of embolism so that proper treatment can be provided as soon as possible. Usually, treatments are designed around the goals of keeping a person breathing and ensuring circulation.

The first step in treating most embolisms is to treat shock and provide oxygen therapy. Anticoagulants are administered that are designed to prevent further clotting. Depending on the patient's status, a surgery called an embolectomy may be performed while the patient is anesthesized. Clot-busting drugs called thrombolytics may also be administered, but they carry a high risk of excessive bleeding.

Specific types of embolism, such as an air embolism, will be treated with recompression using a hyperbarric chamber. Fat embolisms may be also treated with aspirin, steroids, and a ventilation machine.

How can an embolism be prevented?

High risk patients may try various embolism prevention methods, such as taking the drugs heparin or warfarin (anti-coagulants), exercising regularly, wearing anti-embolism compression stockings, and using intermittent pneumatic compression of the legs. Compression methods prevent blood clots by forcing blood into deep veins and reducing the amount of pooled blood. Thrombolytics may also be used to help the body dissolve the original clot.

Video: 3D Medical Animation of DVT & Pulmonary Embolism

Written by Peter Crosta M.A.


Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today