Risk Factors for Pneumonia

A risk factor is something that raises the chances of getting a health problem. A person can get pneumonia with or without the ones listed below. The chances of getting pneumonia are greater in people who have many risk factors.

Pneumonia is more common in babies, young children, and older adults. Other things that may raise the risk are:

Smoking and Secondhand Smoke

People who smoke have a much higher risk of getting pneumonia. Those who stop smoking will have their risk slowly return to normal, but it will take some time. People who are exposed to secondhand smoke are also at risk.

Alcohol and Drug Misuse

Alcohol and drug misuse raise the risk of pneumonia as well as other health problems.

Crowded Living Conditions

The risk of pneumonia is higher among people living in crowded conditions, such as people who live in:

• College dorms
• Long-term care facilities
• Nursing homes
• Military barracks

Health Problems

People who are hospitalized have a much higher risk of getting pneumonia than people who are not. The risk is even higher for people who have had major surgery or who are on ventilators. Other health problems that can raise the risk are:

• Problems that affect gag reflex, such as:
  • Stroke
  • Multiple sclerosis
  • Amyotrophic lateral sclerosis (ALS)
  • Head injury
  • Alzheimer disease
• Problems that weaken the immune system, such as:
  • AIDS
  • A history of organ transplant
  • Cancer, especially leukemia and Hodgkin lymphoma
  • Chemotherapy drugs
  • Medicines that suppress the immune system (including steroids)
• Chronic obstructive pulmonary disease (COPD)
• Diabetes
• Kidney disease
• Sleep apnea
• Heart failure
• Poor nutrition
• Allergies or asthma
• Liver disease
• Mechanical ventilation

Children have a higher risk of getting pneumonia if they have:

• A weakened immune system
• Gastroesophageal reflux disorder (GERD)
• Lung or heart defects
• Allergies or asthma
• Nervous system problems that affect the muscles of the mouth and throat

Genetic Factors

A number of genetic disorders can raise the risk, such as:

• Sickle cell disease
• Cystic fibrosis

Environmental Factors

Exposure to toxic fumes or smoke can weaken the lungs. This can raise the risk of pneumonia.