A pulmonary embolism is a sudden blockage in a lung artery. The cause is usually a blood clot in the leg called a deep vein thrombosis that breaks loose and travels through the bloodstream to the lung. Pulmonary embolism is a serious condition that can cause permanent damage to the affected lung,low oxygen levels in your blood and damage to other organs in your body from not getting enough oxygen.If a clot is large, or if there are many clots, pulmonary embolism can cause death.
Blood clots can form for a variety of reasons. Pulmonary embolisms are most often caused by deep vein thrombosis, a condition in which blood clots form in veins deep in the body. The blood clots that most often cause pulmonary embolisms typically begin in the legs or arms.
Pulmonary embolism symptoms can vary greatly, depending on how much of your lung is involved, the size of the clots (almost never single) and your overall health — especially the presence or absence of underlying lung disease or heart disease.
Common signs and symptoms include:
- Shortness of breath. This symptom typically appears suddenly and always gets worse with exertion.
- Chest pain. You may feel like you're having a heart attack. The pain may become worse when you breathe deeply (pleurisy), cough, eat, bend or stoop. The pain will get worse with exertion but won't go away when you rest.
- Cough. The cough may produce bloody or blood-streaked sputum.
Other signs and symptoms that can occur with pulmonary embolism include:
- Leg pain or swelling, or both, usually in the calf
- Clammy or discolored skin (cyanosis)
- Excessive sweating
- Rapid or irregular heartbeat
- Lightheadedness or dizziness
A detailed history of the patient is taken which includes general health, medical history and symptoms with a physical exam.To confirm the diagnosis of pulmonary embolism, the physician may order specific tests, which may include some of the following:
- Chest x-ray
- Electrocardiography (ECG) which measures your heart’s electrical activity
- D-dimer enzyme-linked immunosorbent assay, a blood test that shows an increase of a type of protein that may rise after a pulmonary embolism
- Lung scanning, which measures blood flow in your lungs and your air intake
- Spiral computed tomography (CT) scan
- Pulmonary angiography, which shows x ray pictures of the blood vessels in your lungs
- Duplex ultrasound, which allows your physician to measure the speed of blood flow and to see the structure of your leg veins
- Venography, which shows x-ray pictures of your leg veins
The most effective way to prevent pulmonary embolism is to prevent DVTs from forming or starting to move in the blood vessels. If you have DVT, you may be prescribed an anticoagulant. Anticoagulants can also be given to people with DVT to prevent the condition. They can also protect against stroke.
Non-medication methods to help prevent DVT include using compression devices and compression stockings (to ensure blood doesn't pool in the legs), and frequently stretching, massaging, and moving your lower leg muscles if you are inactive for a long time. You can also reduce your risk factors for getting blood clots, for instance by quitting smoking and controlling your blood pressure.