Pulmonary embolism is caused by a blood clot that blocks an artery in the lung. It can be fatal if it cuts off the blood supply to a large part of the lung. About 2 out of every 100 cases of pulmonary embolism are fatal.
Most blood clots start as small clots originating in the legs that come loose. The clot travels upwards in the veins, through the heart, and goes into the blood vessels in the lungs. The blood vessel in the lungs get smaller and smaller and the clot finally stops where the blood vessel is so small that the clot cannot get through it. It obstructs the flow of blood at that point and causes an embolus. This embolus cuts off the blood supply to a part of the lung.
Depending on where the clot stops and how large the clot is, the part of the lung, which has lost its blood supply, will no longer function. Rarely, the obstructing particle (called an embolus) is made up of fat, air or tumour cells.
Many cases occur among people already hospitalised for other reasons. A person is more likely to have clots after surgery, stroke, long-term bed rest or inactivity, or fractures of the hip or legs. There is a somewhat higher risk among overweight people and during pregnancy. Those suffering from clotting disorders have an increased risk but usually develop thrombosis or emboli in the situations above. There is also an increased risk among women who take birth control pills and smoke cigarettes.
If a clot lodges in the lungs, there may be sudden shortness of breath, chest pain, coughing up blood, and a low-grade fever. The patient sometimes tightens the chest muscles or avoids deep breathing to diminish pain. The patient may also have some swelling in the legs. A person with a large clot may pass out, appear bluish in colour, or have bulging neck veins.
Most clots resolve after 10 to 14 days. Treatment consists of oxygen therapy and blood thinners that prevent further blood clots. Patients with large clots may need agents that break up the clot. Extreme cases may require emergency surgery.
Anyone recovering from pulmonary embolism, or those at high risk of having one, often take medications that thin the blood for several months. They should consult their doctor before taking any other medications or before engaging in strenuous activities. Keeping as active as possible is the best prevention.
PREVENTION TIPS INCLUDE:
- avoid standing in one position for a long time
- avoid wearing anything on the legs that restricts the return of blood from the feet
- avoid crossing your legs when sitting for an extended period
- take breaks to move your legs on long trips
- walk as soon as possible after surgery (You may need support hose when you walk for a while.)
- if confined to bed, exercise by pushing feet against a board
- elevate your legs now and then
- wear support stockings if advised by your doctor
- follow a low fat diet
- do not smoke
- stay fit and
