Your doctor first will ask about your symptoms. During the physical exam, your doctor will check to see if you are breathing rapidly. He or she also will look for confusion and a purplish hue in your lips, fingernails or hands because these can indicate that you have low levels of oxygen in your blood. Using a stethoscope, a health care professional can listen through your back for abnormal sounds from the lungs.
The diagnosis of pneumonia most often is confirmed by an X-ray. If the chest X-ray does not show pneumonia, but your symptoms and physical exam suggest pneumonia, your doctor may make the diagnosis by looking at sputum (coughed-up mucus) under a microscope or checking if a blood test shows an elevation of infection-fighting white blood cells.
Samples of your sputum or blood also can be sent to a laboratory to identify the specific cause of your pneumonia. Identifying the infectious organism can help your doctor to choose the best antibiotic to treat the infection. However, even when no organism can be identified, the pneumonia still can be treated successfully with antibiotics.
How long pneumonia lasts can vary from a few days to a week or longer, depending on how early a person starts antibiotics and what other medical problems he or she may have. Antibiotic treatment for pneumonia usually lasts from 10 to 14 days. Many people find that it takes a few weeks to several weeks to regain the level of energy they had before the pneumonia.