Pneumonia - Diagnosis

Pneumonia can usually be diagnosed on the basis of a patient's symptoms. A doctor will also listen to the patient's chest with a stethoscope. If the lungs are infected, they produce an unusual sound when the patient breathes in and out. Tapping on the patient's back is also a test for pneumonia. Normally, the tapping produces a hollow sound because the lungs are filled with air. If pneumonia is present, however, the lungs may contain fluid. In this case, the sound is dull thump.

Some forms of bacterial pneumonia can be diagnosed by laboratory tests. A sample of the patient's sputum is taken. The sample is then stained with dyes and examined under a microscope. The organisms causing the disease can often be seen and identified.

X rays can also be used to diagnose pneumonia. Dark spots on the patient's lungs may indicate the presence of an infection. The appearance of the spots may give a clue to the type of infection that has occurred.