A risk factor is something that increases your chance of getting a disease or condition.
It is possible to develop pneumonia with or without the risk factors listed below. However, the more risk factors you have, the greater your chance of developing pneumonia. If you have a number of risk factors, ask your doctor what you can do to reduce your risk.
Smoking and Second-hand Smoke
People who smoke have a much higher risk of developing pneumonia. If you stop smoking, your risk will gradually return to normal. However, this may take as long as 10 years.
You are also at risk for pneumonia if you are regularly exposed to second-hand smoke. For example, children in households where the parents smoke have higher rates of pneumonia than do children in smoke-free households.
Alcohol and Drug Abuse
Crowded Living Conditions
The risk of pneumonia is increased among people living in crowded conditions, such as:
- Students in dormitories
- People living in institutions
- Military personnel in barracks
- People living in nursing homes
People who are hospitalized have a much higher risk of developing pneumonia than do non-hospitalized individuals. This risk is even higher for people who have recently undergone major surgery or who are on ventilators. Other medical conditions that can increase your risk of developing pneumonia include:
- Conditions that interfere with your gag reflex:
- Conditions that weaken your immune system:
- Chronic obstructive pulmonary disease (COPD)
- Kidney disease
- Sleep apnea
- Heart failure
- Poor nutrition
- Generally debilitated state
- Allergies or asthma
- Liver disease
- Mechanical ventilation
Children have a higher risk of developing pneumonia if they have:
- A weakened immune system
- Gastroesophageal reflux disorder (GERD)
- Lung or heart defects
- Allergies or asthma
- Nervous system defects that affect the muscles of the mouth and/or throat
Pneumonia is more common among certain age groups:
- Young children
- Older adults
A number of genetic disorders can predispose you to pneumonia, such as:
Occupational exposure to toxic chemical fumes and/or smoke can weaken your lung’s defenses. This can increase your vulnerability to pneumonia germs.
Community-acquired pneumonia in adults. EBSCO DynaMed website. Available at:http://www.dynamed.com/topics/dmp~AN~T115170/Community-acquired-pneumonia-in-adults. Accessed November 10, 2019.
Community-acquired pneumonia in children. EBSCO DynaMed website. Available at:http://www.dynamed.com/topics/dmp~AN~T113670/Community-acquired-pneumonia-in-children. Accessed November 10, 2019.
Flanders SA, Collard HR, Saint S. Nosocomial pneumonia: state of the science. Am J Infect Control. 2006;34(2):84-93.
Pneumonia symptoms, causes, and risk factors. American Lung Association website. Available at: http://www.lung.org/lung-health-and-diseases/lung-disease-lookup/pneumonia/symptoms-causes-and-risk.html. Accessed November 10, 2019.
Risk factors. National Heart, Lung, and Blood website. Available at: http://www.nhlbi.nih.gov/health/health-topics/topics/pnu/atrisk. Accessed November 10, 2019.
Last reviewed January 2020 by EBSCO Medical Review Board David L. Horn, MD, FACP Last Updated:1/21/2020