Diagnosis

There's no specific test to identify ARDS. The diagnosis is based on the physical exam, chest X-ray and oxygen levels. It's also important to rule out other diseases and conditions — for example, certain heart problems — that can produce similar symptoms.

Imaging

• Chest X-ray. A chest X-ray can reveal which parts of your lungs and how much of the lungs have fluid in them and whether your heart is enlarged.
• Computerized tomography (CT). A CT scan combines X-ray images taken from many different directions into cross-sectional views of internal organs. CT scans can provide detailed information about the structures within the heart and lungs.

Lab tests

A test using blood from an artery in your wrist can measure your oxygen level. Other types of blood tests can check for signs of infection or anemia. If your doctor suspects that you have a lung infection, secretions from your airway may be tested to determine the cause of the infection.

Heart tests

Because the signs and symptoms of ARDS are similar to those of certain heart problems, your doctor may recommend heart tests such as:

• Electrocardiogram. This painless test tracks the electrical activity in your heart. It involves attaching several wired sensors to your body.
• Echocardiogram. A sonogram of the heart, this test can reveal problems with the structures and the function of your heart.