When the alveoli are filled, the lungs can't transfer oxygen to the blood. Consequently, most people with this disease experience shortness of breath when they exert themselves. Some have severe breathing difficulty, even at rest. Most also have a cough that doesn't usually produce sputum unless they're smokers. A chest x-ray shows patchy shadowing in both lungs.
Tests show low levels of oxygen in the blood, at first only during exercise but later at rest, too.
To make the diagnosis, a doctor obtains a sample of the fluid in the alveoli for examination. To obtain a sample, a doctor uses a bronchoscope to wash segments of the lung with a salt solution and then collects the washings. Occasionally, a larger specimen is needed and must be removed surgically. Treatment People who have few or no symptoms don't require treatment. For those with symptoms, the protein-rich fluid in the alveoli can be washed out with a salt solution during bronchoscopy.