Definition

Pneumonia is an infection deep in the small airways and air sacs of the lungs. The infection will make the air sacs swell and fill with fluid or pus. This causes intense coughing. It will also be hard to breathe.

Development of Pneumonia in the Air Sacs of the Lungs Copyright © Nucleus Medical Media, Inc.

Types of pneumonia include:

• Community-acquired—infection is picked up outside of a medical setting; most common type
• Hospital-acquired pneumonia—infection is picked up while in a hospital
• Aspiration —happens when something, such as food, liquid, saliva, or vomit is sucked into the lungs

This article will focus on community-acquired pneumonia.

Causes

Pneumonia is caused by a germ in the air that you breathe. Germs that most often cause community-acquired pneumonia include:

• Viruses—such as flu or cold viruses
• Bacteria
• Fungus—more likely to happen in people with other health issues or immune system problems

Risk Factors

Pneumonia is more common in older adults. Other factors that may increase the chances of pneumonia:

• Living in crowded living conditions such as dormitories or nursing homes
• Smoking
• Being underweight
• Regular contact with children
• Frequent visits to doctor's office
• Alcohol use disorder or drug abuse

Health conditions that may increase the risk of community-acquired pneumonia include:

• Previous pneumonia
• Having certain lung conditions such as chronic obstructive pulmonary disease (COPD) or cystic fibrosis
• Allergies or asthma
• Heart disease or heart failure
• Diabetes
• Weakened immune system including HIV
• Stroke
• Dementia
• Cancer
• Chronic liver disease
• Chronic kidney disease

Other environmental factors include:

• Coming in contact with droppings or dust from:
  • Bats or birds
  • Rabbits
  • Farm animals
• Recent stay in cruise or hotel
• Flu is present in your community

Symptoms

Pneumonia may cause:

• Cough
• Shortness of breath
• Chest pain
• Increased mucus production
• Fever and chills
• Weakness

Diagnosis

The doctor will ask about symptoms and past health. A physical exam will be done. The doctor may suspect pneumonia based on symptoms and lung sounds.

Pictures of the lungs may be taken to confirm the diagnosis or check on pneumonia that is not going away. Pictures may be taken with:

• Chest x-ray
• CT scan

Your doctor may need to know the exact germ that is causing the problem. This step may be needed if there is a severe infection. The germ can be tested through:

• Blood tests
• Test of fluid you cough up
• Urine tests

Treatment

Treatment will be based on what may have caused the pneumonia. More support may be needed if there is a severe infection. A hospital stay may be needed if it becomes difficult to breathe.

Prevention

Vaccines may help to prevent certain pneumonia:

• Flu vaccine—pneumonia can develop after a flu infection, especially people aged 50 years and older
• Pneumococcal vaccine—protects against a specific pneumonia; recommended for:
  • All adults who are aged 65 years or older
  • Adults of any age who are at high risk of infection or have a suppressed immune system

Steps that may decrease the risk for any respiratory infection include:

• If you smoke, talk to your doctor about ways to quit. Smoke damages lung tissue, increases the risk of infection, and increases recovery time.
• Avoid close contact with people who have the cold or flu.
• Wash your hands often. Wash them after contact with someone who is sick.
• Protect yourself on jobs that have risk factors above.
• Follow your treatment plan for lung problems such as asthma and diabetes.