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Pneumonia

Is Pneumonia Contagious?

Eunice Kang, MD, CPHChristine Giordano, MD
Written by Eunice Kang, MD, CPH | Reviewed by Christine Giordano, MD
Updated on December 10, 2025

Key takeaways:

  • Pneumonia is a lower respiratory tract illness that affects the lungs. It can be caused by viruses, bacteria, or, less commonly, fungi. 

  • Pneumonia isn’t contagious. But many germs that cause pneumonia are contagious. 

  • Not everyone who’s exposed to these germs will get sick. People who do get sick may develop other respiratory illnesses, like colds or sinus infections, instead of pneumonia. 

Pneumonia is one of several illnesses that affect the respiratory system. The respiratory system includes your nose, throat, airways, and lungs. You may have many questions if you or someone you love is sick with pneumonia. And one of those questions may be whether you should worry about pneumonia being contagious. 

Pneumonia itself isn’t contagious. But the germs that cause pneumonia can pass from person to person. 

Is pneumonia contagious?

You can’t get pneumonia from someone who has pneumonia. Pneumonia itself isn’t contagious. But many of the viruses, bacteria, and fungi that cause pneumonia are contagious. You can pick up these germs from someone who’s sick with pneumonia. 

But you might not develop pneumonia if you get sick with one of these germs. Viruses and bacteria that cause pneumonia also cause other respiratory illnesses, like:

It’s impossible to predict if someone will develop pneumonia when they get sick with pneumonia-causing germs. But you may be at higher risk for developing pneumonia from one of these germs in the following cases:

  • You’re over age 65.

  • You have a weakened immune system or diabetes.

  • You have chronic obstructive pulmonary disease (COPD), asthma, or another lung condition.

  • You have a chronic heart or liver condition.

  • You smoke.

You’re also more likely to develop pneumonia if you haven’t been vaccinated against viruses and bacteria that can cause pneumonia. 

How does pneumonia spread?

Pneumonia doesn’t spread. But the viruses and bacteria that cause pneumonia can spread from person to person. Here’s how this works.

Viruses

Viruses that cause pneumonia spread through respiratory droplets. When someone is sick and they talk, sneeze, or cough, they expel tiny droplets of water. These droplets contain viruses and bacteria. If another person breathes in these droplets, they can get sick too. 

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Viruses that cause pneumonia include:

People with viral pneumonia are most contagious for the first few days of their illness. Most people stop being contagious after about a week. 

Bacteria 

Some bacteria that cause pneumonia also spread through respiratory droplets. For example, Mycoplasma pneumoniae spreads through respiratory droplets and is a major cause of walking pneumonia. Streptococcus pneumoniae can also spread through respiratory droplets. It can cause severe pneumonia.

But other bacteria that cause pneumonia don’t spread this way. Legionella is a bacteria that can cause serious pneumonia. Legionella grows in water and can contaminate common items like air conditioners, whirlpools, hot tubs, and humidifiers. You can only get sick with legionella if you breathe in water droplets from water sources that are contaminated with the bacteria. 

People with bacterial pneumonia can spread the bacteria until they start treatment with antibiotics. People stop being contagious after taking antibiotics for 48 hours

Fungi

Some fungi can also cause pneumonia. The most common causes of fungal pneumonia are:

These fungi don’t pass from person to person. Fungal pneumonia is never contagious. You can only get sick with fungal pneumonia by breathing in these fungi from sources like contaminated soil

How long is pneumonia contagious?

It depends on the type of pneumonia. Pneumonia caused by a fungal infection doesn’t pass from person to person. Someone with bacterial pneumonia may be able to spread germs until 48 hours after starting antibiotics. Viruses that cause pneumonia may be transmitted until symptoms (including fever) improve. 

What can you do to prevent pneumonia?

Pneumonia can be a very serious illness. But there are steps you can take to lower your risk of developing pneumonia. Many actions that help prevent illnesses from the flu or COVID-19 will also lower your risk of getting sick with pneumonia. These include:

  • Frequent handwashing

  • Not touching your eyes, nose, and mouth

  • Avoiding people who are sick

  • Disinfecting frequently touched surfaces

You can also avoid getting pneumonia by keeping your immune system strong by:

  • Getting enough sleep

  • Eating foods that are rich in vitamins and minerals

  • Not smoking and limiting alcohol

It’s also important to stay up-to-date with vaccinations. Vaccines that protect against viruses and bacteria that cause pneumonia can keep you healthy. Consider getting vaccinated against:

  • RSV 

  • The flu

  • COVID

  • Pneumococcus

Your healthcare team can help you decide if one or more of these vaccines is right for you.

Frequently asked questions

Adults can get pneumonia when a bacteria, virus, or fungus causes an infection inside the lungs. People with lung conditions or weakened immune systems are more likely to develop pneumonia. 

Walking pneumonia is a term to describe a mild form of pneumonia. The name comes from the idea that since symptoms are mild, a person is likely to still be walking around doing their normal activities. 

Yes, the virus that causes the flu can infect the lungs and cause pneumonia. You can reduce your risk of developing pneumonia from the flu by getting a yearly flu vaccine.

The bottom line

Pneumonia is a lung infection that can be caused by viruses, bacteria, and fungi (this is less common). Pneumonia itself isn’t contagious. But many of the viruses and bacteria that can lead to pneumonia are contagious. You can lower your risk of getting pneumonia by washing your hands, avoiding people who are sick, and staying up-to-date with vaccines.

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Why trust our experts?

Eunice Kang, MD, CPH, practiced internal medicine before transitioning to clinical research. She has worked as a residency program director at Norwalk Hospital, and has taught at Yale University and the University of Vermont.
Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.
Christine Giordano, MD, is board-certified in general internal medicine. She received her medical degree from Rutgers New Jersey Medical School and completed residency at Thomas Jefferson University.

References

GoodRx Health has strict sourcing policies and relies on primary sources such as medical organizations, governmental agencies, academic institutions, and peer-reviewed scientific journals. Learn more about how we ensure our content is accurate, thorough, and unbiased by reading our editorial guidelines.

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