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Lung Disease & Respiratory Health Center

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Bacterial Pneumonia

Exams and Tests

Pneumonia can often be diagnosed simply by a doctor listening to your lungs. Certain sounds heard through a stethoscope may indicate infection.

  • One of the easiest tests to perform is pulse oximetry, sometimes called "pulse ox." A probe that looks like a clothespin is gently attached to your finger, toe, or ear. A special light shines through your skin to estimate how much oxygen you have in your bloodstream. If your oxygen level is lower than expected, it may mean you have pneumonia.
  • An X-ray of your chest can help identify which part of your lung is infected. An X-ray also can show abnormal fluid collections, which also can help diagnose pneumonia.
  • You may have blood drawn. Laboratory tests can show that your immune system is working properly to fight off your infection. Certain lab tests can also show whether you have enough red blood cells to carry oxygen or whether the bacteria have gotten into your bloodstream.
  • Occasionally your doctor may need to sample blood from one of your arteries (usually in your wrist) in order to get an exact measurement of how well you are exchanging oxygen and carbon dioxide. This test, called an arterial blood gas ("ABG" or "blood gas"), is very important, takes only a minute, and is done with a very small needle and syringe. This test cannot be run on the other blood that is sampled from your veins.
  • Sometimes your doctor will collect some of your sputum and look at it under a microscope. Certain stains, or dyes, help your doctor tell which specific bacterium is causing your pneumonia. Your sputum also may be put on a plate to help it grow, so a laboratory specialist can look at it under a microscope and identify the specific bacteria.

Bacterial Pneumonia Treatment: Self-Care at Home

If you suspect pneumonia based on the signs or symptoms, see your doctor as soon as possible. There is no home treatment for pneumonia. Although cough suppressants, expectorants, or fever-lowering drugs may be helpful, they should not be started without discussing their use with your doctor.

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