Pulmonary embolism is a condition in which a blood clot blocks one of the arteries in the lungs. It is also commonly referred to as a lung embolism. In some cases, it can develop suddenly and lead to serious health problems, which is why early diagnosis and prompt treatment are important.
To understand pulmonary embolism, it is important to know where the clot usually comes from. In most cases, the clot does not form inside the lungs. It typically develops in the deep veins of the legs, especially in the calf or thigh region. This condition is called deep vein thrombosis (DVT).
A clot formed in the leg can break loose and travel through the bloodstream. It first reaches the right side of the heart and is then carried into the lung arteries. Because the pulmonary arteries gradually become narrower, the clot may eventually get stuck and block blood flow. This blockage is called pulmonary embolism.
The severity of pulmonary embolism depends on the size of the blocked artery. Smaller clots may cause milder symptoms, while larger clots affecting major pulmonary arteries can have a more significant impact on circulation.
What are the symptoms?
Symptoms of pulmonary embolism can vary from person to person. In some patients, symptoms appear suddenly, while in others they develop more gradually. The most common symptom is sudden shortness of breath. Patients may feel unable to breathe comfortably even while resting.
Chest pain is also common. The pain often becomes worse with deep breathing, coughing, or movement. Some patients describe it as sharp or stabbing pain. A rapid heartbeat is another frequent finding, as the heart may need to work harder to maintain circulation through the lungs.
Cough may occur, and some patients may cough up blood. This can develop due to the effect of the clot on lung circulation. Larger clots may lead to dizziness, fainting, cold sweating, bluish discoloration of the lips, or marked weakness. These symptoms may indicate a more serious condition and require urgent medical evaluation.
Some patients also have swelling, redness, or tenderness in one leg. Swelling affecting only one calf is particularly suggestive of deep vein thrombosis. Symptoms are not always severe; some patients may experience only mild shortness of breath. For this reason, people at risk should not ignore newly developed breathing difficulties.
Who is at risk?
Pulmonary embolism is usually associated with conditions that increase the tendency for blood clot formation.
Prolonged immobility is one of the most important risk factors. Long-distance travel, recovery after surgery, extended bed rest, or leg casts can slow blood circulation in the legs and increase the risk of clot formation.
The risk of pulmonary embolism is particularly increased after hip, knee, and abdominal surgeries. Preventive treatments are therefore commonly used after major operations. Estrogen-containing birth control pills and hormone therapies may also increase the tendency for clotting, and smoking further increases this risk.
Pregnancy and the postpartum period are also associated with a higher risk of blood clots. Hormonal changes and slower blood flow contribute to this increased risk.
Cancer can increase the tendency of the blood to clot in some individuals. Chemotherapy, prolonged hospitalization, and immobility may further contribute to the risk.
A previous history of pulmonary embolism or deep vein thrombosis increases the likelihood of recurrence. Some individuals may also have inherited clotting disorders, especially if there is a family history of blood clots at a young age.
Obesity, smoking, older age, and prolonged immobility are additional factors that may contribute to risk.
How is pulmonary embolism diagnosed?
When pulmonary embolism is suspected, rapid evaluation is important because its symptoms may resemble those of other conditions.
The first step is assessing symptoms and risk factors. Doctors ask about recent surgery, long-distance travel, medications, and family history.
One commonly used blood test is the D-dimer test. A low D-dimer level makes pulmonary embolism less likely, although a high level alone does not confirm the diagnosis.
The most important test for confirming the diagnosis is CT pulmonary angiography. In this imaging study, a contrast dye is injected into a vein so that the pulmonary arteries can be visualized and checked for clots.
In some situations, a ventilation-perfusion scan may be used. This test compares airflow and blood flow in the lungs to identify areas affected by clots. Ultrasound of the leg veins may also help detect deep vein thrombosis.
Echocardiography can be useful, especially in larger pulmonary emboli, to evaluate how the right side of the heart is affected.
How is pulmonary embolism treated?
Treatment depends on the severity of the condition. Blood thinners are the foundation of pulmonary embolism treatment. These medications prevent the clot from growing and allow the body time to gradually dissolve it. They also reduce the risk of forming new clots.
In the early phase of treatment, injectable blood thinners are often used first, followed later by oral medications. Modern blood thinners have made long-term treatment easier for many patients.
In some large pulmonary emboli, clot-dissolving medications may be considered, especially when circulation is significantly affected. In selected patients, catheter-based procedures may also be used to break up or remove the clot directly.
Treatment duration varies depending on the underlying cause. Some patients require treatment for three months, while others may need longer-term anticoagulation.
Is pulmonary embolism dangerous?
The severity of pulmonary embolism depends on the size of the clot and the patient’s overall condition.
Small and moderate pulmonary emboli can often be managed successfully when diagnosed early and treated appropriately. Many patients are able to return to normal life after treatment.
Some large pulmonary emboli may seriously affect circulation and require intensive treatment. Untreated or delayed cases can sometimes lead to long-term pressure elevation in the lung arteries.
Early diagnosis and proper treatment significantly improve outcomes.
Can it happen again?
People who have had pulmonary embolism have a higher risk of recurrence compared with the general population. This risk depends largely on the underlying cause.
Pulmonary embolism associated with temporary risk factors, such as surgery or prolonged travel, tends to have a lower recurrence risk. Cases without a clear trigger may carry a higher long-term risk.
To reduce recurrence risk, it is important to stay active during long trips, maintain hydration, and avoid prolonged immobility. Smoking cessation, weight control, and regular physical activity may also help reduce clotting risk.
What should patients know while taking blood thinners?
Blood thinners are a key part of pulmonary embolism treatment, but they require careful use because they increase bleeding risk.
Nosebleeds, gum bleeding, unusual bruising, or blood in the urine should be reported to a doctor.
Some pain medications, antibiotics, and herbal supplements can interact with blood thinners. Patients should consult their physician before starting any new medication.
Before dental procedures or surgery, the management of blood thinners should be planned by the treating physician. These medications should never be stopped without medical advice.
In older patients, taking precautions to reduce the risk of falls can also be helpful.
Pregnancy and pulmonary embolism
Pregnancy increases the risk of blood clot formation. Hormonal changes and slower circulation contribute to this effect, particularly during the first weeks after delivery.
If pulmonary embolism develops during pregnancy, treatment must be carefully planned. Heparin-type medications are generally preferred because some oral blood thinners are not considered safe during pregnancy.
Women with a previous history of pulmonary embolism should be evaluated by a physician before planning pregnancy.
When should medical attention be sought?
Sudden shortness of breath, especially when it persists at rest, requires medical evaluation.
Chest pain that worsens with deep breathing, coughing up blood, or shortness of breath accompanied by palpitations should prompt urgent medical attention.
Swelling, redness, and pain in one leg may indicate deep vein thrombosis and should also be evaluated.
Patients taking blood thinners should seek medical advice if significant bleeding develops.
Fainting, bluish lips, or severe cold sweating require urgent medical evaluation.
Frequently Asked Questions
Can long flights cause pulmonary embolism?
Long flights may increase clot risk, especially in people with other risk factors. Staying active, drinking enough water, and using compression stockings when needed may help reduce this risk.
How long does treatment last?
Treatment duration depends on the underlying cause. Some patients require three months of treatment, while others may need longer-term therapy.
Can I exercise after pulmonary embolism?
After the acute phase, appropriate exercise is generally encouraged. Avoiding prolonged immobility is important.
Can I stop blood thinners on my own?
No. Blood thinner treatment should always be managed under medical supervision.