Pulmonary edema happens when fluid builds up in the air pockets (alveoli) of the lungs. This fluid impairs the oxygen/carbon dioxide exchange process described in my emphysema article. Pulmonary edema usually occurs as a result of heart problems particularly heart failure where blood pressure increases in the lungs and fluid pushed into the air pockets in the lungs.
The Causes of Pulmonary Edema
Conditions such as pneumonia can also result in pulmonary edema, as well as direct physical injury to the lung. Exercising at very high altitudes can also cause pulmonary edema (www.nlm.nih.gov). Pulmonary edema may appear as a side effect of a heart attack, leaking or narrow heart valves, or any other disease of the heart (such as cadiomyopathy) that results in the weakening or stiffening of the heart muscle.
Other conditions that may result in pulmonary edema include:
Acute respiratory distress syndrome where the structural integrity of the alveoli is compromised because of severe infections, trauma, injury to the lungs, inhalation of toxins, lung infections, cocaine smoking, or radiation to the lungs.
Kidney failure which compromises the body's ability to cleanse itself of excess fluid
Trauma to the brain resulting in intracranial hemorrhage (bleeding), severe seizures, or surgery can correspondingly result in "neurogenic" pulmonary edema
When a lung collapses (pneumothorax) or a large amount of fluid around the lung (pleural effusion) is removed and the lung expands rapidly, the affected side may experience pulmonary edema
Overdosing on Aspirin, or those who habitually take a high dose of Aspirin may lead to Aspirin intoxication and pulmonary edema.
Other conditions include: heroin or methadone overdose, pulmonary embolism, transfusion-related acute lung injury, some viral infections, or eclampsia in pregnant women
There is a long list of symptoms associated with pulmonary edema including (this list compiled from www.nlm.nih.gov and www.mayoclinic.com):