Diagnosis

Breathing problems require immediate diagnosis and treatment. Your doctor can make a preliminary diagnosis of pulmonary edema based on your signs and symptoms and the results of a physical exam, electrocardiogram and chest X-ray.

Once your condition is more stable, your doctor will ask questions about your medical history, especially whether you have ever had cardiovascular or lung disease.

Tests that may be done to diagnose pulmonary edema or to determine why you developed fluid in your lungs include:

• Chest X-ray. A chest X-ray can confirm the diagnosis of pulmonary edema and exclude other possible causes of your shortness of breath. It's usually the first test done when someone has signs or symptoms of pulmonary edema.
• Chest CT. A computed tomography (CT) scan of the chest may not provide the cause for the pulmonary edema, but can give your doctor indirect clues to help make a diagnosis.
• Pulse oximetry. A sensor is attached to your finger or ear and uses light to determine how much oxygen is in your blood.
• Arterial blood gas test. Blood is taken, usually from an artery in your wrist, and checked for the amount of oxygen and carbon dioxide it contains (arterial blood gas concentrations).
• B-type natriuretic peptide (BNP) blood test. Increased levels of BNP may signal a heart condition.
• Other blood tests. Blood tests to diagnose pulmonary edema and its causes also usually include a complete blood count, metabolic panel to check kidney function and thyroid function test.
• Electrocardiogram (ECG or EKG). This painless test detects and records the timing and strength of your heart's signals using small sensors (electrodes) attached to the skin on your chest and legs. The signals are recorded in the form of waves on graph paper or a monitor. An ECG can show signs of heart wall thickening or previous heart attack. A portable ECG machine such as a Holter monitor may be used to continuously monitor your heartbeat at home.
• Echocardiogram. An echocardiogram creates a moving picture of your heart using sound waves (ultrasound). It can identify areas of poor blood flow, abnormal heart valves and heart muscle that is not working normally. Your doctor can use this test to help diagnose fluid around the heart (pericardial effusion).

• Cardiac catheterization and coronary angiogram. This test may be done if an ECG, echocardiogram or other tests don't show the cause of pulmonary edema, or if you also have chest pain.

  During cardiac catheterization, a doctor inserts a long, thin tube (catheter) in an artery or vein in your groin, neck or arm. X-rays help guide the catheter through the blood vessel to your heart. During a coronary angiogram, dye flows through the catheter, allowing blood vessels to show up more clearly on the X-rays. A coronary angiogram can reveal any blockages and measure the pressure in your heart chambers.

• Ultrasound of the lungs. This painless test uses sound waves to measure blood flow through the lungs. It can quickly reveal signs of fluid buildup and plural effusions. Lung ultrasound has become an accurate tool for diagnosing pulmonary edema.