Pulmonary Embolism
Pulmonary embolism is a blockage in an artery in the lungs. It occurs when a blood clot – usually from the legs (deep vein thrombosis) – breaks off, is carried through the bloodstream and lodges in the arteries in the lungs. This blocks the flow of blood through the heart, which may lead to death.


Pulmonary embolism is a blockage in an artery in the lungs. It occurs when a blood clot – usually from the legs (deep vein thrombosis) – breaks off, is carried through the bloodstream and lodges in the arteries in the lungs. This blocks the flow of blood through the heart, which may lead to death.
Symptoms
- Chest pain (often sudden)
- Shortness of breath
- Sharp pain that worsens when taking a deep breath
- Coughing up blood


- Chest pain (often sudden)
- Shortness of breath
- Sharp pain that worsens when taking a deep breath
- Coughing up blood
Risk Factors
- Age, especially over the age of 60
- Presence of deep vein thrombosis or previous deep vein thrombosis
- Certain inherited conditions, such as factor V Leiden
- Previous pulmonary embolism
- Recent treatment for cancer
- Presence of a central venous catheter, a tube that is placed in a vein for some medical treatments
- Sitting for long periods of time (for example in a car or on an airplane)
- Pregnancy, including the six week period after pregnancy
- Hormone therapy
- Birth control pills
- Obesity
Complications
Massive pulmonary embolism causes an overload of the heart and can cause a sudden collapse of the cardiovascular system, which can cause fainting or sudden death.
Treatments
- Oxygen is usually given – through a tube, through a mask or, in severe cases of low oxygen levels, through a ventilator
- Blood thinners
- Blood pressure elevators
- “Clot buster” medications (thrombolytics) for the most serious cases
For further information please consult following chapters of Layman’s Handbook of Venous Disorders:
- Chapter 2: Risk Factors for Venous Thrombosis
- Chapter 3: Clotting disorders
- Chapter 6: Clinical Presentation of Venous Thrombosis “Clots”: Deep Venous Thrombosis and Pulmonary Embolus
- Chapter 7: Medical Treatment of Deep Vein Thrombosis and Pulmonary Embolus
- Chapter 9: Indications for Inferior Vena Cava Interruption
Learn more from our Handbook.