Pulmonary Embolism: Causes, Symptoms, and Treatment

Pulmonary embolism is the blockage of one of the arteries in your lungs by a blood clot. This clot, which usually breaks off from the deep vessels in your legs (deep vein thrombosis – DVT) and reaches the lungs through blood circulation, blocks blood flow to a part of your lungs. This condition can create a life-threatening situation by causing sudden and severe symptoms such as shortness of breath and chest pain. However, it can be successfully managed with early diagnosis and proper treatment.

In this article, we will comprehensively discuss what pulmonary embolism is, its symptoms, causes, diagnosis and treatment methods, risk factors, and when you should see a doctor.

What is Pulmonary Embolism?

Pulmonary embolism is the sudden blockage of an artery in your lungs by a blood clot. This clot usually consists of a piece that breaks off from the deep veins in your legs. This clot, carried to the lungs with blood flow, prevents lung tissue from receiving oxygen and makes it difficult for your heart to pump blood to the lungs. Pulmonary embolism can produce results ranging from mild discomfort to sudden death.

What Causes Pulmonary Embolism?

Pulmonary embolism occurs when blood flow to your lungs is blocked. Usually, its primary source is a clot formed in the veins in your legs, namely deep vein thrombosis (DVT). The main factors causing DVT are slowing of blood flow, damage to the vessel wall, or blood clotting more easily than normal. Especially prolonged immobility, major surgeries, injuries, pregnancy, some types of cancer, and genetic predispositions increase this risk.

The most common causes of pulmonary embolism are:

Deep Vein Thrombosis (DVT):

Most pulmonary embolism cases occur when a clot formed in the deep veins in your legs breaks off and reaches the lungs. DVT can occur as a result of the following conditions:

• Prolonged Immobility: Conditions such as long airplane or car trips, being bedridden, or being in a cast slow blood flow and prepare the ground for clot formation.
• Surgery and Injuries: Major operations, especially hip and knee replacement surgeries, can damage blood vessels and increase the risk of clotting.
• Cancer and Its Treatment: Some types of cancer and chemotherapy can increase the blood’s tendency to clot.
• Pregnancy: Increased hormone levels during pregnancy and the pressure of the uterus on leg vessels increase DVT risk.
• Hormone Treatments: Birth control pills containing estrogen or hormone replacement therapies can increase the blood’s tendency to clot.
• Genetic Predisposition: If there is a family history of DVT or pulmonary embolism, your risk increases in terms of clotting disorders.

What are the Symptoms of Pulmonary Embolism?

Pulmonary embolism symptoms vary according to the size of the clot and the degree of blockage in your lungs. The most common symptoms are sudden-onset shortness of breath, chest pain, cough, and rapid pulse. Chest pain usually increases with deep breathing and can be confused with heart attack pain. If these symptoms appear suddenly and severely, getting emergency medical help is of vital importance.

The symptoms of pulmonary embolism are:

• Sudden-Onset Shortness of Breath: Usually appears suddenly while at rest or during light activity.
• Chest Pain: Usually sharp, stabbing pain that worsens with deep breathing, coughing, or movement.
• Cough: May be accompanied by bloody sputum.
• Rapid or Irregular Heartbeat: Your heart tries to beat faster to compensate for the blockage in the lungs.
• Dizziness, Fainting, or Feeling of Lightheadedness: Occurs due to insufficient oxygen reaching the brain.
• Swelling, Pain, or Tenderness in the Leg: DVT symptoms, especially swelling, pain, and feeling of warmth in one leg.
• Pallor or Blueness in the Skin: Color changes in the skin may occur due to the body lacking oxygen.

How is Pulmonary Embolism Diagnosed?

Pulmonary embolism diagnosis begins with the evaluation of your symptoms and risk factors. Your doctor uses various tests to make a quick and accurate diagnosis. The most commonly used tests include D-Dimer blood test, computed tomography (CT) angiography, and ultrasound. These tests allow us to determine the presence, location, and severity of the clot. Early and accurate diagnosis is life-saving.

The main methods used in pulmonary embolism diagnosis are:

• D-Dimer Blood Test: Shows the presence of clot breakdown products in the blood. A normal D-Dimer test result largely rules out the possibility of DVT or pulmonary embolism. However, a high D-Dimer result alone is not sufficient for diagnosis and requires additional tests.
• Computed Tomography (CT) Angiography: This is the most commonly used and most reliable imaging method in pulmonary embolism diagnosis. A special contrast agent is injected into your vessels to obtain detailed images of your pulmonary arteries, and the presence of clots is clearly detected.
• Leg Ultrasonography: Ultrasound is performed on your leg vessels to find the source of the clot causing pulmonary embolism. It shows the presence, location, and size of the clot in leg vessels.
• Electrocardiogram (ECG): The ECG test is performed to rule out other emergency conditions such as heart attack and to see how your heart is affected by pulmonary embolism.
• Lung Ventilation/Perfusion (V/Q) Scan: This is a nuclear medicine method used when CT angiography cannot be performed. It shows the presence of clots by evaluating both air flow (ventilation) and blood flow (perfusion) in your lungs.

How is Pulmonary Embolism Treated?

The main goal of pulmonary embolism treatment is to prevent the clot from growing, prevent the formation of new clots, and prevent life-threatening complications. The foundation of treatment consists of blood-thinning medications (anticoagulants). These medications do not help dissolve the clot but support your body’s natural mechanisms to dissolve the clot. In more serious cases, clot-dissolving medications or interventional methods can be used.

The main methods used in pulmonary embolism treatment are:

Blood-Thinning Medications (Anticoagulants):

• These medications reduce the blood’s ability to clot, preventing the clot from growing and preventing the formation of new clots.
• Treatment usually lasts at least 3-6 months but may last longer depending on your risk factors.
• Treatment usually begins with injections (low molecular weight heparin), then transitions to oral medications (Warfarin or new generation oral anticoagulants – DOACs).

Thrombolytic Therapy (Clot-Dissolving Medications):

• In life-threatening, severe pulmonary embolism cases, medications that directly dissolve the clot are used.
• These medications are given intravenously or directly into the clot through a catheter. They require close monitoring in the hospital due to high bleeding risk.

Embolectomy (Clot Removal Surgery):

• Very rarely, in cases where drug treatment is not effective or the clot is very large, the clot is surgically removed. In this method, the clot is extracted using special devices. The catheter method can be life-saving in high-risk patients in shock.

Vena Cava Filter:

• In very special cases where blood-thinning medications cannot be used or the risk of the clot going to the lungs continues despite medication, a temporary or permanent filter can be placed in the vena cava, the main vein. This filter is designed to prevent clots coming from the legs from reaching the lungs.

Who Gets Pulmonary Embolism More Frequently?

It is more common in people who remain bedridden for long periods, patients who have undergone surgery, and the elderly age group. Cancer patients, women going through pregnancy and postpartum period are also at risk. Additionally, the likelihood of developing pulmonary embolism increases in individuals with congenital clotting disorders.

What Should Be Considered After Treatment?

Blood-thinning treatment should be continued regularly during the recovery period. If long-term bed rest is required, intermittent movement should be provided. Consuming plenty of fluids, taking frequent walks, and staying away from cigarettes reduces the risk of clot formation. Regular doctor visits increase treatment success.

Does Pulmonary Embolism Lead to Serious Consequences?

Pulmonary embolism can lead to serious and potentially life-threatening complications, especially if not treated promptly or if the clot is large. The severity of complications depends on the size and location of the clot, how much lung tissue is affected, and your overall health condition. Understanding these potential risks emphasizes the importance of seeking immediate medical attention when symptoms occur.

The main risks and complications of pulmonary embolism include:

Acute Complications:

• Right Heart Failure (Acute Cor Pulmonale): When lung vessels are blocked, your heart’s right side has to work much harder to pump blood through the remaining open vessels. This increased workload can cause the right ventricle to enlarge and fail, leading to decreased cardiac output and potentially fatal cardiovascular collapse.
• Cardiogenic Shock: In massive pulmonary embolism cases, the sudden blockage of major lung arteries can cause severe drop in blood pressure, inadequate tissue perfusion, and shock. This is a medical emergency requiring immediate intensive care.
• Sudden Cardiac Death: Large clots that block major pulmonary arteries can cause immediate cardiovascular collapse and death if not treated within minutes. This occurs in approximately 10% of pulmonary embolism cases.
• Respiratory Failure: Significant blockage of lung circulation can lead to severe oxygen deficiency (hypoxemia) and carbon dioxide retention, requiring mechanical ventilation support.

Chronic Complications:

• Chronic Thromboembolic Pulmonary Hypertension (CTEPH): This is a rare but serious long-term complication where organized clot material remains in the lung arteries, causing persistently high pressure in the pulmonary circulation. This leads to progressive right heart failure and significantly impacts quality of life.
• Post-Pulmonary Embolism Syndrome: Some patients develop chronic shortness of breath, reduced exercise tolerance, and fatigue that can persist for months or years after the initial event. This may be related to permanent lung damage or psychological factors.
• Recurrent Pulmonary Embolism: Patients who have had one episode are at increased risk for future episodes, especially if underlying risk factors persist or anticoagulation therapy is inadequate.

Treatment-Related Complications:

• Bleeding Complications: Blood-thinning medications necessary for treatment can cause significant bleeding, ranging from minor bruising to life-threatening internal hemorrhage, particularly in the brain, gastrointestinal tract, or surgical sites.
• Paradoxical Embolism: In rare cases, aggressive clot-dissolving treatment can cause clot fragments to travel to other parts of the body, potentially causing stroke or other organ damage.

The risk of these complications highlights why pulmonary embolism is considered a medical emergency requiring immediate diagnosis and treatment. Early intervention significantly reduces mortality and the likelihood of long-term complications.

Does Pulmonary Embolism Recur?

If risk factors are not eliminated in a person who has had pulmonary embolism, the likelihood of recurrence is high. Irregular use of blood-thinning medications or failure to treat underlying clotting tendency increases the risk of recurrence. Recurring embolisms can cause permanent damage to lung vessels.

Does Pulmonary Embolism Completely Heal?

Pulmonary embolism can completely heal when treated correctly and timely. As the clot dissolves, body tissues also recover and respiratory function returns to normal in most patients. However, if the clot is large or treatment is delayed, permanent damage to the lung may occur. The healing process may vary according to the person and the severity of the disease.

When Should You See a Doctor?

Sudden-onset shortness of breath, sharp chest pain, cough, and rapid heartbeat are the most important warning signs of pulmonary embolism. If you are experiencing these symptoms alone or several together, you should get emergency medical help. Pulmonary embolism is a time-critical condition and rapid intervention can be life-saving. Especially if you have recently had surgery or taken a long trip and these symptoms appear, it is very important to take the situation seriously.

You need to see a doctor or emergency room immediately in the following situations:

• Sudden and Unexplained Shortness of Breath: If you have difficulty breathing even during rest.
• Sharp Pain in the Chest: If you experience pain that increases with deep breathing and feels like a heart attack.
• Cough of Unknown Cause: Especially if accompanied by bloody sputum.
• Palpitations or Rapid Heartbeat: If you feel your pulse speeding up.
• Fainting or Feeling of Lightheadedness: Especially sudden-onset conditions that create confusion of consciousness.
• Symptoms in the Leg: If you observe DVT symptoms such as swelling, pain, warmth, or redness in your leg.

Reference: Pulmonary Embolism