Pneumonia

What Is Pneumonia?

Pneumonia is a lung infection that occurs because of a virus, bacteria, or fungus.

Before the COVID-19 pandemic, about 1.5 million people received a pneumonia diagnosis in the ER each year. This is about two to three out of every 1,000 people.

Some pneumonia cases are mild, while others can be severe — or even deadly.

It's the eighth most common cause of death in the U.S., claiming the lives of about 50,000 people each year. During very bad flu seasons, deaths from pneumonia are much higher.

Pneumonia is also the most common cause of hospitalization in the U.S. after giving birth.

Types of pneumonia

There are three basic types of pneumonia, based on how someone gets the infection:

• Community-acquired pneumonia occurs when a person becomes infected outside of a health care setting.
• Healthcare-acquired pneumonia occurs when a person gets infected while in a hospital, nursing home, or other healthcare settings.
• Ventilator-acquired pneumonia occurs when a person gets the disease while on a machine that helps them breathe.

Pneumonia causes

An infection causes pneumonia but there are many possible causes of the infection, including viruses, bacteria, and fungi.

Many viruses can cause pneumonia but the most common are:

• Flu
• COVID-19
• RSV

Several different types of bacteria can also cause pneumonia.

The repeated use of antibiotics can cause certain types of resistant bacterial pneumonia. You should only receive antibiotics if doctors know what bacteria caused your pneumonia.

Some people can be at risk for pneumonia due to a fungus, especially when their immune system is weak.

Sometimes doctors never find out what kind of germ caused a person's pneumonia.

Pneumonia risk factors and complications

Anyone can develop pneumonia as a complication of an infection.

About one-half of all people who get pneumonia are between the ages of 18 and 57. And about half the people who die from bacterial pneumonia are 18 to 64 years old.

People with a higher risk of pneumonia include those who:

• Are 65 years old or older.
• Smoke or who spend time around people who smoke.
• Have a weakened immune system.
• Take medicine that weakens or suppresses their immune system.
• Are receiving treatment for cancer.
• Have received an organ transplant.
• Have breathed in toxic chemicals recently or frequently over time.

People with the following chronic health conditions also have a higher risk of pneumonia:

• COPD.
• Diabetes.
• Congestive heart failure.
• Cancer.
• Sickle cell anemia.
• HIV/AIDS.
• Conditions that weaken the immune system.

If people with pneumonia don't receive treatment, many will form complications — and some may even die.

People who get pneumonia in the hospital often have a higher risk of dying than those who get it in the community.

Pneumonia complications

Pneumonia is also the most common cause of sepsis, a very serious condition that can cause death. Sepsis occurs when the immune system overreacts to an infection.

Even if you receive treatment for pneumonia, some people suffer long-term such as:

• Feeling tired or not being able to exercise as much.
• Other lung diseases.
• Heart disease.
• Poor quality of life.
• Trouble thinking or concentrating.

How to prevent pneumonia

The best and most vital way to prevent certain types of pneumonia infections is to get the vaccines for the following diseases:

• Flu.
• COVID-19.
• Pneumococcal.
• H. influenzae type b (Hib) in children.
• Measles.
• Chickenpox.
• Pertussis or whooping cough.

Other things you can do to reduce your risk of catching pneumonia are to:

• Avoid people who are sick, especially if you have a weak immune system.
• Wash your hands routinely.
• Avoid touching your eyes, nose, mouth, or face often.
• Clean surfaces that people touch often.
• Quit smoking or stay away from people who smoke.
• Maintain your home's air conditioners, humidifiers, fountains, or water pipes.
• Follow your doctor's instructions for managing asthma, diabetes, and heart disease (if you have any of these).