Pneumonia diagnosis

If you or your healthcare provider suspect that you may have pneumonia, your provider will likely begin to diagnose the condition^[11] by listening to your signs and symptoms, and consulting your medical history. They will likely also conduct a physical exam, which may include listening to your lungs with a stethoscope to check for abnormal breathing sounds, which may indicate pneumonia. If they do suspect that pneumonia is a possibility, your healthcare provider may conduct or recommend some of the following tests:

• Blood tests: Blood testing can be used to measure your white blood cell count. An elevated level of white blood cells often indicates that your body is fighting off an infection. Other blood tests can also confirm whether you have pneumonia by identifying the presence of the particular organism causing the infection (although identifying exactly what type of infection you have isn't always possible).
• Chest X-ray: This diagnostic test is the gold standard for detecting pneumonia. A chest X-ray can be used to detect the presence of pneumonia, as well as the severity and location of the infection. This type of test, however, cannot go so far as to detect the specific pathogen (virus, bacteria, or other intruding substance) that is causing your condition.
• Pulse oximetry: This type of test measures the level of oxygen in your blood. Because pneumonia can prevent your lungs from passing sufficient oxygen into your bloodstream, a low blood oxygen concentration can help indicate the presence of the infection.
• Sputum test: This test involves analyzing a sample of fluid from your lungs (sputum) after a deep cough. A sputum test can be used to determine what specific bacteria or virus is causing your infection.

Your provider might recommend or order additional testing if you are older than 65, currently hospitalized, have serious symptoms, or have pre-existing health conditions. Further testing may include:

• CT scan: If your pneumonia symptoms are slower to improve than anticipated, your provider may recommend using a chest CT scan to obtain a more detailed image of your lungs.
• Pleural fluid culture: This test involves inserting a needle between your ribs to take a sample of fluid from the pleural area. This sample is then analyzed to help determine the type of infection you have.

Is pneumonia contagious?

Most types of pneumonia are contagious. Specifically, bacterial and viral pneumonia are contagious^[12], because bacteria and viruses can pass easily from person to person. The infection can be passed from direct contact (usually by the hands) or by inhaling droplets in the air from someone’s cough or sneeze. Fungal pneumonia is typically not contagious. That’s because the fungi is inhaled from your environment, not spread to others from infected individuals. Aspirational pneumonia is also not typically contagious because it is caused by inhaling liquid or chemicals into your lungs.

Pneumonia in children

While pneumonia can happen at any age, it is more common in young children^[13] and elderly people. Pneumonia in children is especially serious if it affects their breathing. Children may be hospitalized if they:

• Are younger than 6 months old
• Are lethargic or excessively sleepy
• Have trouble breathing
• Have low blood oxygen levels
• Appear dehydrated or are unable to feed or maintain oral hydration
• Have underlying conditions like cardiopulmonary disease
• Have worsened with outpatient therapy (within 48–72 hours after completing the treatment regimen)

If your child has not had the yearly influenza vaccine or has not been immunized for streptococcus pneumoniae bacteria, they are at higher risk for pneumonia. To help prevent your child from getting pneumonia, make sure they get vaccinated^[14]. Providers recommend a specific pneumococcal vaccine called Prevnar-13, which is a 4-dose series that is typically spaced throughout the child’s first 15 months of life. It is part of a routine pediatric immunization schedule recommended by the Center for Disease Control and Prevention. In some circumstances, older children may receive Prevnar-13 as directed by a physician if they have missed doses, or if they have other conditions that put them at a higher risk of getting pneumonia. It is highly recommended that children who spend time in childcare centers be vaccinated. Providers also recommend regular flu shots for children older than 6 months of age. Newborn babies and infants may not show any sign of pneumonia. If they do present symptoms, they may vomit, cough, have a fever, appear restless or tired, or have difficulty breathing and eating.