There are several different ways that your doctor can diagnose pneumonia. There are some previous health or recent lifestyle issues like the flu, a cold, surgery or travel that can tip your doctor off to the possibility that what you are presenting with is pneumonia, and your diagnosis may be made solely on a review of these issues. There are also several tests that can be performed to help the doctor confirm that what you have is pneumonia, determine which kind of pneumonia it is, and prescribe a course of treatment.
The doctor may order a chest x-ray which will show the lungs as well as other organs, bones and tissue.
Blood tests are taken to verify the presence of infection, and to see if that infection has spread to the bloodstream. Blood tests will also check the amount of oxygen in your bloodstream. Another, more refined way of measuring oxygen in the blood is called pulse oximetry, which uses a small machine called an oximeter to measure oxygen.
A sputum (or spit) culture is taken on the mucous or phlegm that has been coughed up from the lungs and into the mouth; culturing the sample is another way to determine if there is an infection present in the lungs.
A chest CT scan, also known as tomography, is a more advanced type of x-ray that shows more detail than a standard chest x-ray does. A CT scan is a noninvasive procedure that shows the physician the shape, size and position of your lungs and can also help further clarify any abnormal findings that may have been seen on a previous x-ray. Chest CT scans help the doctor to determine the cause of chest pain and shortness of breath; they are also used to check for other lung problems like excess fluid on the lungs, a blood clot in the lungs, a tumor, emphysema or tuberculosis.
A bronchoscopy is a procedure that examines the lungs’ main airway (the bronchi) by using a flexible tube to take tissue samples or fluids from the area for examination. This helps your physician further hone in on the diagnosis and evaluate and diagnose problems in the lungs.
A pleural fluid culture also evaluates fluid in the lungs, but the fluid is taken by a syringe attached to a long, thin needle that has been inserted between the ribs. This is way of finding out which type of bacteria is causing the pneumonia.