Pneumonia Center


In the United States, about 3 million cases of pneumonia are reported each year. Pneumonia ranges in severity from mild to severe, and it can be fatal. Very young children, adults over 65, and patients who have a chronic illness are particularly vulnerable to pneumonia. But what is pneumonia? And what types of pneumonia do doctors diagnose?

What is pneumonia?
A normally functioning lung provides oxygen to the blood while it simultaneously removes carbon dioxide from the bloodstream. Pneumonia is a general term that refers to inflammation of the lungs. Pneumonia can affect one or both lungs. When inflammation occurs in the lungs, fluid and pus made of destroyed white blood cells can collect and interfere with the trading of oxygen and carbon dioxide in the blood.

Types of pneumonia
Doctors refer to pneumonia by the way in which a person gets the infection or for the germ that causes it.

Aspiration pneumonia - This type of pneumonia occurs when you accidentally inhale food, drink, vomit, or saliva from the mouth into the lungs. Aspiration pneumonia can cause a lung abscess and typically occurs after brain injury, excessive use of alcohol or drugs, or if you are diagnosed with a swallowing problem. This type of pneumonia is also present among newborns and infants as they often regurgitate milk and may inhale it.

Atypical pneumonia - Several types of bacteria cause this type of pneumonia, which is passed from person to person. This type of pneumonia is characterized by common symptoms of pneumonia but requires additional testing to confirm a diagnosis.

Community acquired pneumonia (CAP) – Community acquired pneumonia is the most common type of pneumonia and occurs outside of health care settings. Most people get CAP by breathing in germs that live in the mouth, nose, or throat. CAP is often transmitted while sleeping; most cases occur during the winter as people tend to gather together indoors.

Hospital acquired pneumonia (HAP) - Some people catch pneumonia while being hospitalized for another illness, especially while using a mechanical ventilator. Cases of HAP tend to be more serious because you’re already sick and the germs that cause this type of pneumonia tend to be resistant to antibiotics.

Health care associated pneumonia – This type of pneumonia refers to pneumonia which is transmitted in other health care settings, such as nursing homes, dialysis centers, and outpatient clinics.

How do people get pneumonia and who is at risk? Click here to learn more about how pneumonia is transmitted and the different causes of pneumonia.

NEXT: Causes and Risk Factors >>