Usually, your doctor will diagnose pneumonia by doing a physical exam and then performing additional tests if needed. The physical exam includes:
- Listening to the chest while you breathe to detect any abnormal bubbling or cracking sounds in the lungs
- Measuring your temperature to detect fever
- Speaking with you to determine how long you have had a cough and how it has progressed
There are several tests your doctor may perform if pneumonia is suspected:
- Chest X-ray: creates an image of the lungs. Doctors can visually inspect this image for signs of pneumonia. X-rays can also help determine the extent of the infection.
- Pulse oximetry: uses a small sensor that attaches to the finger or ear. It uses light to estimate how much oxygen is present in the blood. This can be helpful because pneumonia can prevent the lungs from getting enough oxygen into the bloodstream.
- Blood test: a sample of blood is taken and inspected in a laboratory for the presence of viruses, bacteria, or other organisms. The results can often show what type of organism is causing the pneumonia.
- Sputum tests: a sample of sputum or mucus is taken and inspected in a laboratory to help find the cause of the pneumonia.
- Pleural fluid culture: a sample of the fluid in the lungs is taken by putting a needle in-between your ribs and withdrawing a small amount of fluid. This sample is then examined in a laboratory.
- Computed tomography (CT) scan: involves scanning your chest and creating a more detailed image of the lungs. This is done if your pneumonia is not resolving as quickly as expected.