Pulmonary Embolism: Causes, Treatments, and Resources

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What is a Pulmonary Embolism

Pulmonary embolism (PE) is the third most common cause of death in hospitalized patients. It is not easily diagnosed. In the United States, it has an average annual incidence of one per one thousand, with about 250,000 cases occurring annually. Additionally, autopsy studies show that besides these cases initially diagnosed by clinicians, an additional equal number of patients are diagnosed with this health problem following autopsy. These findings have thus led to estimates of between 650,000 to 900,000 fatal and nonfatal incidences of this disease occurring in the US annually, with similar figures cited in foreign countries.

Derived from the Greek word “embolos” meaning “stopper” or “plug,” embolism refers to a clot that forms in one part of the body and travels in the bloodstream to another part of the body. Pulmonary embolism from the Latin term “pulmonarius,” meaning “of the lungs” occurs when there is a sudden blockage in a lung artery due to a blood clot that traveled to the lung from a vein in the leg. If left undiagnosed and untreated, about 30 percent of patients who have it will die. Worse, most of the fatalities die within the first few hours of the event.

But before one goes into the hows and whys of PE, it is important to first track the route of blood through the body. Blood travels from the heart to the lungs through the pulmonary arteries. Blood picks up oxygen from the lungs, then goes back to the heart from where the blood is pumped to the rest of the body, providing critical oxygen to the body tissues. Thus, when clots or emboli, especially large ones, find their way to the blood vessels and wedge to form a blockage, blood is prevented from flowing into the rest of the lung. And the part of the lung that does not receive enough oxygen dies, an event that’s called pulmonary infarction.

Causes of a Pulmonary Embolism

Pulmonary embolism occurs when a clump of material, most often a blood clot, gets wedged into an artery in your lungs. These blood clots most commonly originate in the deep veins of your legs, but they can also come from other parts of your body. This condition is known as deep vein thrombosis (DVT).

Occasionally, other substances can form blockages within the blood vessels inside your lungs. Examples include:

Fat from within the marrow of a broken bone
Part of a tumor
Air bubbles

What Type Of People Are More Likely To Get a Pulmonary Embolism

Some individuals are more likely to get pulmonary embolism than others. But it must be noted that the majority of PE cases can be traced to another condition known as deep vein thrombosis or DVT, a blood clot usually found in the deep veins of the leg that’s formed if the blood flow is restricted or slows down. Unlike clots in the veins close to the skin’s surface, which do not move and are harmless, these deep vein clots can break loose, travel through the bloodstream to the lungs, and block an artery. The three main risk factors in DVT-induced pulmonary embolism include: prolonged immobilization, increased blood clotting potential and damage to the vessel wall.

Prolonged immobilization usually happens after an extended hospital stay or bed rest and extended travel. A condition or injury that results in confinement to bed enables clots to form in either the arms or legs. So too does prolonged travel, in which sitting in an airplane or a long car trip allows the blood to sit in the legs and increases the risk of clot formation. Some individuals also have greater potential for developing blood clots, including those who are past age 60 or have a genetic predisposition; those who are on birth control pills or estrogen therapy; those who have undergone surgery or cancer treatment; those who are suffering from obesity, heart disease such as irregular heartbeat, and burns; those who are pregnant or are in the six-to-eight-week postpartum stage; as well as smokers. Finally, individuals who have a prior history of deep venous thrombosis or have experienced trauma to the lower leg without surgery or casting are also more likely to develop clots.

It must be remembered that artery-blocking emboli can be formed not just by blood clots but also by other material, including fat that can escape into the blood from the bone marrow in case of bone fracture or during bone surgery, amniotic fluid forced into the pelvic artery during traumatic childbirth, cancer cells that may break free into the circulation, air bubbles that may result if a catheter in a large vein is inadvertently open to air, infected material that may come from intravenous drug use, among others and foreign substances introduced into the bloodstream.

Symptoms of a Pulmonary Embolism

One who suffers from a pulmonary embolism manifests this condition through a whole range of symptoms, including shortness of breath, chest pains, coughing sometimes with blood, irregular heartbeat or arrhythmia and, in DVT-related PE, tenderness and swelling of the affected leg, which may also be sometimes reddish or warm. Some PE sufferers may also experience lightheadedness or fainting, sweating, rapid breathing or accelerated heart rate. More severe pulmonary embolism cases may result in shock, passing out, cardiac arrest, and death.

Common signs and symptoms

1. Shortness of breath. This symptom typically appears suddenly, and occurs whether you’re active or at rest.

2. Chest pain. You may feel like you’re having a heart attack. The pain may become worse when you breathe deeply, cough, eat, bend or stoop. The pain will get worse with exertion but won’t go away when you rest.

3. Cough. The cough may produce bloody or blood-streaked sputum.

Other signs and symptoms that can occur with pulmonary embolism

Wheezing
Leg swelling
Clammy or bluish-colored skin
Excessive sweating
Rapid or irregular heartbeat
Weak pulse
Lightheadedness or fainting

Treatment of Pulmonary Embolism

While pulmonary embolism may be treated, mainly through anticoagulants or blood thinners, as with most medical conditions, prevention is key. And the most important step is gaining awareness: If one knows that one is at risk for DVT, one can take steps to lower this risk, including exercising the lower leg muscles during long trips or a long confinement, taking clot-preventing medicines, and visiting the doctor for regular check-ups.

Resources about Pulmonary Embolisms

Images of a Pulmonary Embolism

Mayo Clinic information about a Pulmonary Embolism

MedicineNet Information about Pulmonary Embolisms answering questions such as:

What is a pulmonary embolism?
What are the causes and risk factors for pulmonary embolism?
What are the signs and symptoms of pulmonary embolism?
How is pulmonary embolism diagnosed?
History and physical examination

Basic testing (CBC, electrolytes, BUN, creatinine blood test, chest x-ray, EKG)
Pulmonary angiogram
d-Dimer blood test
CT Scan
Ventilation-perfusion scans
Venous Doppler study
Echocardiography (EKG, ECG)

How is pulmonary embolism treated?
Anticoagulation
Thrombolytic therapy

What is the prognosis for pulmonary embolism?
Can pulmonary embolism be prevented?

Resource by L.Fuller

I am a fanatic when it comes to fitness and nutrition. I enjoy going to the gym, working out, hiking, camping, and overall just learning how to stay happy and healthy.

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