Pulmonary embolism

Pulmonary embolism at a glance

Pulmonary embolism occurs when a lung vessel is suddenly blocked. Large, central embolisms block important arteries in the lung and can rapidly lead to acute, life-threatening circulatory stress. Smaller, peripheral embolisms tend to affect the outer areas of the lungs and can cause a pulmonary infarction or an inflammatory reaction. There are three main types of pulmonary embolism, depending on the cause of the blood vessel blockage:

• Thromboembolism: by far the most common type, it is triggered by a blood clot (thrombus).
• Fat embolism (rare): occurs when fat droplets enter the bloodstream, for example after fractures or orthopaedic surgery.
• Air or gas embolism (very rare): caused by air or gas bubbles entering the body, e.g. during catheter procedures or diving accidents.

Thromboembolic pulmonary embolism (also known as thromboembolism) is discussed below.

Causes of pulmonary embolism

In most cases, pulmonary embolism occurs as a result of venous thrombosis. If a blood clot breaks loose from a deep leg or pelvic vein, it can travel through the bloodstream to the lungs. If the blood clot blocks a vessel there, an embolism occurs.

Three factors in particular contribute to the development of thrombosis: changes in vessel walls, reduced speed of blood flow and an increased tendency towards clotting. Situations that encourage these conditions, such as surgery, injury, tumour disease or prolonged immobilisation, increase the risk of venous thrombosis.

Detailed information on the causes of thrombosis can be found on the thrombosis disease pattern page.

Symptoms of pulmonary embolism

As pulmonary embolism often occurs as a result of venous thrombosis, it’s important to take the early signs of a blood clot seriously. Typical symptoms, such as heaviness in the legs, swollen or overheated lower legs and pain in the calves or back of the knees, can be signs of deep vein thrombosis. If such symptoms occur after surgery, a longer flight or periods of immobility, immediate medical clarification is urgently recommended. You can find more information on detecting thrombosis on the disease pattern page.

If an embolism occurs as a result of venous thrombosis, the symptoms usually change dramatically. Symptoms typically appear suddenly and can vary in severity depending on the extent of the thrombosis. Common symptoms include:

• Shortness of breath
  Sudden onset of shortness of breath, which initially only occurs under physical exertion and later also at rest.
• Chest pain
  Acute chest pain, which usually occurs when breathing and gets worse when inhaling. The pain can be sharp and is often mistaken for a heart attack.
• Coughing
  A cough in conjunction with the above symptoms or with bloody sputum.
• Dizziness or loss of consciousness
  Dizziness or short fainting spells can occur because the heart can no longer pump enough blood due to the increased pressure.
• Accelerated heartbeat
  A rapid pulse (tachycardia) occurs because the heart tries to compensate for the lack of oxygen.
• Strong feeling of anxiety (e.g. fear of death)
  Many patients report acute, pronounced feelings of anxiety or even fear of death. These are caused by severe shortness of breath and circulatory stress and are a typical accompanying symptom.

Gender-specific symptoms of pulmonary embolism

Although the incidence of pulmonary embolism is similar in women and men overall, there are differences in the risk profile and typical symptoms. In women, for example, hormonal factors often play a key role, such as taking contraceptives containing oestrogen, pregnancy or the postpartum period. There are also gender-specific differences in how symptoms are perceived.

Pulmonary embolism symptoms in women

Women more frequently report non-specific symptoms such as increased shortness of breath, severe tiredness, general weakness or a feeling of pressure or tightness in the chest. These signs do not always appear suddenly and are therefore sometimes attributed to other causes, such as stress, infections or heart problems.

Pulmonary embolism symptoms in men

Male patients, on the other hand, are more likely to experience acute, sharp chest pain, significant shortness of breath or circulatory disorders.

Diagnosing a pulmonary embolism

Pulmonary embolism is usually diagnosed by specialists in pneumology or cardiology and begins with a detailed medical history. This is followed by a physical examination that includes, among other things, measuring blood pressure and pulse, and examining the lungs. Various diagnostic procedures are then used:

• Blood test (D-dimer test)
  This involves measuring D-dimers, which are by-products created when the body actively dissolves a blood clot. Elevated levels may indicate thrombosis or pulmonary embolism, but can also occur in other inflammatory illnesses.
• Electrocardiogram (ECG)
  An electrocardiogram records the heart’s electrical activity. It can show changes typical of a pulmonary embolism, especially if the right side of the heart is under strain.
• Computed Tomography (CT)
  Computed tomography is the most important imaging technique for diagnosing pulmonary embolism. With the help of contrast agents administered by a radiologist, blood clots in the pulmonary vessels can be precisely displayed.
• Cardiac ultrasound (echocardiography)
  An echocardiogram is used to assess the function and strain of the right side of the heart. It can indicate the extent to which the vessel blockage is impairing circulation.

Treatment of pulmonary embolism

The treatment of pulmonary embolism always depends on the severity of the thrombosis and the individual risk profile of the patient.

Treatment of mild to moderate pulmonary embolism

In less severe cases, pulmonary embolism can usually be treated successfully with blood-thinning medications (anticoagulants). This process is also called thrombolysis. They prevent the blood clot from growing and allow the body to break it down by itself. Commonly used medications are heparin or direct oral anticoagulants (DOACs).

Treatment for severe pulmonary embolism

In the case of severe or life-threatening pulmonary embolism, or if thrombolysis is not possible, a catheter can be pushed through a vein into the pulmonary artery. There, the clot can either be broken up mechanically or dissolved locally with a lower dose of medication.

Prevention

As pulmonary embolism often results from deep vein thrombosis, the most important prevention begins with thrombosis prevention. Reducing the risk of thrombosis automatically reduces the risk of pulmonary embolism.

• Movement: if you’re confined to bed for a longer period or have limited mobility, regularly moving your feet and legs and walking short distances help stimulate blood flow.
• After surgery: compression stockings support venous return and reduce the risk of thrombosis.
• When travelling: even during long journeys or flights, take breaks, stand up and move your legs actively.
• Avoid smoking: this is particularly important if you’re also taking hormonal medications.
• Strive for a healthy body weight: being overweight increases the risk of thrombosis and venous ailments.
• Anticoagulant medications: in certain higher-risk situations, prophylactic anticoagulants may be useful, but this is always decided on the recommendation of a doctor.

Pulmonary embolism FAQ