What is a pulmonary embolism? 

A pulmonary embolism is a condition where a blood vessel in your lungs becomes blocked, which is most often caused by a blood clot that has travelled from another part of your body. This blockage can prevent blood from flowing correctly to the lung tissue, affecting oxygen levels in the bloodstream and putting strain on the heart. Understanding the signs of this condition is vital for ensuring that medical help is sought quickly when symptoms appear. 

What We’ll Discuss in This Article 

• The primary physical symptoms associated with a pulmonary embolism. 

• Common causes and how blood clots typically form in the body. 

• Factors that may increase an individual’s risk of developing a clot. 

• The clinical methods used by medical professionals to diagnose the condition. 

• How healthcare providers typically treat a blockage in the lung. 

• When it is necessary to seek immediate emergency medical assistance. 

Symptoms of a pulmonary embolism 

A pulmonary embolism typically causes sudden breathlessness, chest pain that worsens when breathing in, and a cough that may produce blood. These symptoms occur because the blockage restricts blood flow, making it difficult for the lungs to oxygenate the body efficiently. The severity of these symptoms often depends on the size of the clot and how much of the lung is affected by the blockage. 

In addition to respiratory distress, individuals may experience a rapid heartbeat, feeling lightheaded or dizzy, and a general sense of anxiety or unease. Some people may also notice symptoms of a blood clot elsewhere in the body before the lung symptoms start, such as pain, redness, or swelling in one leg. Because these signs can overlap with other health conditions, a formal medical evaluation is required to confirm the cause. 

Common causes and risk factors 

The most frequent cause of a pulmonary embolism is a blood clot in the leg, known as deep vein thrombosis (DVT), which breaks free and travels through the bloodstream to the lungs. While the body naturally forms clots to stop bleeding after an injury, certain conditions can cause clots to form inappropriately inside the veins. These clots usually develop in the deep veins of the legs or pelvis before migrating to the pulmonary arteries. 

Several factors can increase the likelihood of developing these clots. Being inactive for long periods, such as during a long flight or following a major operation, can slow blood flow and encourage clotting. Other risk factors include pregnancy, certain types of cancer, smoking, and using hormonal treatments like the combined contraceptive pill or hormone replacement therapy. Having a family history of blood clots or being overweight can also elevate an individual’s risk profile. 

How a pulmonary embolism is diagnosed 

Medical professionals use a combination of physical examinations, blood tests, and imaging scans to determine if a patient has a pulmonary embolism. The diagnostic process often begins with a review of the patient’s medical history and an assessment of their symptoms and risk factors. A specific blood test known as a D-dimer test is frequently used to look for fragments of blood clots in the bloodstream, although this test alone cannot confirm where a clot is located. 

If a blockage is suspected, imaging is necessary to visualise the blood vessels in the lungs. A CT pulmonary angiogram (CTPA) is a common scan used in the UK, involving a special dye injected into the veins to show blood flow through the lungs on an X-ray. In some cases, a ventilation-perfusion (VQ) scan may be used instead to measure both airflow and blood flow in the lungs. These tests help doctors determine the exact location and size of the embolism to plan appropriate treatment. 

Treatment options for blood clots in the lung 

The primary treatment for a pulmonary embolism involves the use of anticoagulant medicines, which help to stop the clot from getting larger while the body slowly dissolves it. These medications, often referred to as blood thinners, do not actually thin the blood but rather change the chemical balance to prevent new clots from forming. Treatment usually lasts for several months, though some individuals may need to stay on medication longer if they have a high risk of recurrence. 

In more severe cases where the blockage is very large or life-threatening, doctors may use treatments to dissolve or remove the clot more quickly. Thrombolytic medicines can be administered to break down the clot rapidly, though these carry a higher risk of bleeding. Occasionally, a surgical procedure or a catheter-directed treatment may be performed to physically remove the blockage from the pulmonary artery. Following the initial treatment, patients are often monitored to ensure their oxygen levels and heart function return to normal. 

Conclusion 

A pulmonary embolism is a serious medical condition involving a blockage in the lung’s blood vessels, typically originating from a clot in the leg. Recognising the signs of sudden breathlessness and chest pain is essential for ensuring prompt medical intervention and starting anticoagulant treatment. By managing risk factors and staying active, individuals can help reduce the likelihood of clot formation. 

If you experience severe, sudden, or worsening symptoms, call 999 immediately. 

Authority Snapshot 

This article was created to provide the general public with clear and accurate information regarding the symptoms and causes of pulmonary embolism. The content is written by a UK-trained physician and reviewed for clinical accuracy, ensuring all information aligns with current NHS and NICE standards. Our goal is to promote health awareness and safety through evidence-based guidance.