(Community-acquired Pneumonia; CAP; Bronchopneumonia)
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.
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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.
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
- Fungus—more likely to happen in people with other health issues or immune system problems
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
- 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
- Weakened immune system including HIV
- Chronic liver disease
- Chronic kidney disease
Other environmental factors include:
Coming in contact with droppings or dust from:
- Bats or birds
- Farm animals
- Recent stay in cruise or hotel
- Flu is present in your community
Pneumonia may cause:
- Shortness of breath
- Chest pain
- Increased mucus production
- Fever and chills
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:
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 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.
Medicine can help to fight some infections:
- Antibiotics—for pneumonia caused by bacteria
- Antifungal medications—for pneumonia caused by a fungus
- Antiviral medications—for pneumonia caused viruses such as the flu
Other medicine may help to manage symptoms:
- Over-the-counter medications to reduce fever and discomfort
- Vitamin C may be advised if you do not get enough in your diet
Severe infections can make it hard for oxygen to get into the body. Oxygen may be given to improve levels in the blood.
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.
American Lung Association
Centers for Disease Control and Prevention
Public Health Agency of Canada
The Lung Association
Blasi F, Aliberti S, Pappalettera M, Tarsia P. 100 years of respiratory medicine: pneumonia. Respir Med. 2007;101(5):875-881.
Community-acquired pneumonia in adults. EBSCO DynaMed website. Available at: http://www.dynamed.com/topics/dmp~AN~T115170/Community-acquired-pneumonia-in-adults. Accessed January 29, 2021.
De Roux A, Marcos MA, Garcia E, et al. Viral community-acquired pneumonia in non-immunocompromised adults. Chest. 2004;125(4):1343-1351.
Immunization schedules. Centers for Disease Control and Prevention website. Available at: https://www.cdc.gov/vaccines/schedules/index.html. Accessed January 29, 2021.
Niederman MS. Recent advances in community-acquired pneumonia inpatient and outpatient. Chest. 2007;131(4):1205-1215.
Niederman MS. Review of treatment guidelines for community-acquired pneumonia. Am J Med. 2004;117:Suppl 3A:51S-57S.
Pneumonia. National Heart, Lung, and Blood Institute website. Available at: https://www.nhlbi.nih.gov/health-topics/pneumonia. Accessed January 29, 2021.
2/3/2015 DynaMed Plus Systematic Literature Surveillancehttp://www.dynamed.com/topics/dmp~AN~T116217/Allergic-rhinitis: Rantala A, Jaakkola JJ, Jaakkola MS. Respiratory infections in adults with atopic disease and IgE antibodies to common aeroallergens. PLoS One. 2013;8(7):e68582.
Last reviewed March 2021 by EBSCO Medical Review Board David L. Horn, MD, FACP Last Updated: 1/29/2021