Tests and diagnosis

By Mayo Clinic Staff

Because pulmonary edema requires prompt treatment, you'll initially be diagnosed on the basis of your symptoms and a physical exam, electrocardiogram and chest X-ray.

Once your condition is more stable, your doctor will ask 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 will likely be the first test you have done to confirm the diagnosis of pulmonary edema and exclude other possible causes of your shortness of breath.
  • Pulse oximetry. In pulse oximetry, a sensor attached to your finger or ear uses light to determine how much oxygen is in your blood.
  • Blood tests. You may have blood drawn, usually from an artery in your wrist, so that it can be checked for the amount of oxygen and carbon dioxide it contains (arterial blood gas concentrations).

    Your blood may also be checked for levels of a substance called B-type natriuretic peptide (BNP). Increased levels of BNP may indicate that your pulmonary edema is caused by a heart condition.

    Other blood tests may be done — including tests of your kidney function, thyroid function and blood count — as well as tests to exclude a heart attack as the cause of your pulmonary edema.

  • Electrocardiogram (ECG). This noninvasive test can reveal a wide range of information about your heart. During an ECG, patches attached to your skin receive electrical impulses from your heart. These are recorded in the form of waves on graph paper or a monitor. The wave patterns show your heart rate and rhythm and whether areas of your heart show diminished blood flow.
  • Echocardiogram. An echocardiogram is a noninvasive test that uses a wand-shaped device called a transducer to generate high-frequency sound waves that are reflected from the tissues of your heart. The sound waves are then sent to a machine that uses them to compose images of your heart on a monitor.

    The test can help diagnose a number of heart problems, including heart valve problems, abnormal motions of the ventricular walls, fluid around the heart (pericardial effusion) and congenital heart defects.

    It can also show areas of diminished blood flow in your heart and if your heart pumps blood effectively when it beats. It can also estimate if there's increased pressure in the right side of the heart and increased pressure in the pulmonary arteries.

  • Transesophageal echocardiography (TEE). In a traditional cardiac ultrasound exam, the transducer remains outside your body on the chest wall. But in TEE, a doctor inserts a soft, flexible tube (catheter) with a transducer attached to the tip through your mouth and guides it into your esophagus — the passage leading to your stomach.

    The esophagus lies immediately behind your heart, which allows your doctor to see a closer and more accurate picture of your heart and central pulmonary arteries.

  • Pulmonary artery catheterization. If other tests don't reveal the reason for your pulmonary edema, your doctor may suggest a procedure to measure the pressure in your lung capillaries (wedge pressure).

    During this test, a doctor inserts a small, balloon-tipped catheter through a vein in your leg or arm and guides it into a pulmonary artery. The catheter has two openings connected to pressure transducers. The balloon is inflated and then deflated, giving pressure readings.

  • Cardiac catheterization. If tests such as an ECG or echocardiography don't uncover the cause of your pulmonary edema, or you also have chest pain, your doctor may suggest cardiac catheterization and coronary angiogram.

    During cardiac catheterization, a doctor inserts a long, thin catheter in an artery or vein in your groin, neck or arm and threads it through your blood vessels to your heart using X-ray imaging. Doctors then inject dye into the blood vessels of your heart to make them visible under X-ray imaging (coronary angiogram).

    During this procedure, doctors can perform treatments such as opening a blocked artery, which may quickly improve the pumping action of your left ventricle. Cardiac catheterization can also be used to measure the pressure in your heart chambers, assess your heart valves and look for causes of pulmonary edema.

July 24, 2014