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Quick Facts



The Manual's Editorial Staff

Last full review/revision Sep 2019| Content last modified Sep 2019
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What is pneumonia?

Pneumonia is an infection deep in your lungs. The infection involves the small air sacs in your lungs (alveoli). Pneumonia is different from infection of the air passages (bronchi) in your lungs. Infection of the air passages is called bronchitis.

Inside the Lungs and Airways

Inside the Lungs and Airways

With pneumonia:

  • You usually cough up mucus

  • You have chest pain, chills, fever, or trouble breathing

  • Your symptoms can be very mild (sometimes called "walking pneumonia") or very serious

  • Symptoms are often worse in young children, older people, and people with other lung problems such as COPD

  • Most people recover, but pneumonia can be fatal

Every year, about 60,000 people in the United States die from pneumonia.

What causes pneumonia?

Pneumonia can be caused by many different types of germs, including:

  • Viruses (most common)

  • Bacteria

Usually, the germs are passed from one person to another. If you touch something that has germs on it, the germs can get in your mouth, nose, or throat. Usually, your body fights off the germs. But sometimes the germs get in your lungs and cause an infection.

What are the risk factors for getting pneumonia?

Anyone can get pneumonia, but it's more likely if you have a weakened immune system because you are:

  • Very young or very old

  • Taking certain drugs (such as corticosteroids or chemotherapy drugs)

  • Have HIV

  • Weakened by having other serious illnesses (such as diabetes or heart failure)

Other risk factors for pneumonia include:

  • Being in a hospital for a long time (where you're exposed to lots of germs)

  • Being on a breathing machine (ventilator)

  • Having a serious lung disease, particularly COPD

  • Smoking

What are the symptoms of pneumonia?

  • Feeling run down

  • Fever and chills (shivering so hard your teeth chatter)

  • A cough that may or may not bring up mucus

  • Trouble breathing (feeling like you can't get enough air in)

  • Pain in your chest

Symptoms may be a little different in people who are very old:

  • They may not have a fever

  • Older adults may be confused and may not think clearly

How can doctors tell if I have pneumonia?

To find out if you have pneumonia, your doctor will:

  • Listen to your lungs as you breathe

  • Usually give you a chest x-ray

If you're sick enough with pneumonia to be admitted to the hospital, doctors usually do blood tests and send samples of your sputum (stuff you cough up) to the lab.

How do doctors treat pneumonia?

Doctors treat pneumonia with:

  • Antibiotics that work best for the type of germ that’s causing the problem (but not all germs that cause pneumonia can be killed by antibiotics)

  • Medicines to help with fever or pain

  • Sometimes extra fluids or oxygen

You may need a chest x-ray about 6 weeks after treatment to make sure the pneumonia is gone, especially if you smoke or are older.

Most people can stay home during treatment. Some people may stay in the hospital, including people who:

  • Are very young or very old

  • Have another serious health problem, such as cancer

  • Have very serious pneumonia symptoms

How can I keep from getting pneumonia?

If you smoke, stop smoking.

Get a yearly flu vaccine (shot), because having the flu can lead to pneumonia. Ask your doctor whether you also need a pneumonia vaccine, which is recommended for:

  • All children before age 6

  • Adults 65 or older

  • People of any age who have certain health problems

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