An Overview of Pneumonia

Pneumonia is an illness that affects millions of people each year. Although it is one of the top 10 causes of death among adults when combined with the flu, its severity can actually vary widely. There are many different types of pneumonia and it affects people of all ages. Since it is such a common—but often condition, you really need to know what it is, what to do if you get it, and how you can prevent it.

What Is Pneumonia?

View infected airways and pus production with pneumonia.

Pneumonia is an infection or inflammation of the lungs. It can affect just one section of your lungs (lobar pneumonia) or sections throughout both lungs (multilobar pneumonia). When you have pneumonia, air sacs in your lungs fill with pus or other liquids and oxygen has trouble reaching your blood.

Who Is Affected?

People of all ages can get pneumonia.

Those at highest risk include:

  • Anyone over 65 years old
  • Anyone with a suppressed immune system
  • Children under two years old
  • Anyone with heart or lung disease
  • Anyone with alcoholism
  • Anyone with kidney failure
  • Anyone with HIV
  • Anyone with diabetes
  • Alaskan natives and certain Native American populations

Causes of Pneumonia

Pneumonia can be caused any number of things. Unlike most common illnesses that have a distinct cause (the flu is caused by the influenza virus, strep throat is caused by the streptococcus bacteria, etc.), pneumonia can be caused by viruses, bacteria, fungus, mycoplasmas, or even chemicals.

How Pneumonia Is Spread

In most cases, people get pneumonia because they have another respiratory illness like the flu. When a person's body defenses are weakened by the flu, bacteria can invade the lungs and cause pneumonia. In some cases, germs can be passed from person to person, causing pneumonia to spread through the air. This is most common with mycoplasma pneumonia.

What to Expect

The symptoms of pneumonia may differ depending on what is causing it, but some common symptoms may include:

Many cases require prescription medications for treatment, so you must see a doctor to be diagnosed with and treated for pneumonia. Moreover, you may need extra oxygen or medicine that will help you breathe better. And although most people are able to be treated at home, some people need to stay in the hospital.

Duration of Symptoms

The exact duration of pneumonia varies depending on what type it is and your overall health prior to getting sick.

According to the American Lung Association, "most healthy people recover from pneumonia in one to three weeks, but pneumonia can be life-threatening." A majority of bacterial pneumonia cases resolve with treatment in one to three weeks.

Mycoplasma pneumonia, also known as "walking" pneumonia, may last four to six weeks. Viral pneumonia can last even longer but is typically not as severe as bacterial pneumonia.

If You Think You Have Pneumonia

If you think you might have pneumonia, contact your health care provider or seek medical attention. Only a health care provider can diagnose pneumonia and determine the appropriate treatment plan. Treatment will be based on the cause and severity of the illness.

If you have been diagnosed, are being treated and not feeling better after a few days on antibiotics (specifically if you have bacterial pneumonia), or you have developed new symptoms, contact your healthcare provider again.

Pneumonia is the leading cause of vaccine-preventable death in the United States.

Although it can't be prevented 100 percent of the time, there is a vaccine available to help people who are at high risk avoid some of the most serious causes.

What You Can Do to Prevent Pneumonia

If you are not in a high-risk group, simple measures to protect yourself from illness—such as washing your hands, avoiding people who are seriously ill, and getting your flu vaccine—can go a long way.

Although the flu vaccine doesn't prevent pneumonia (it only protects against influenza), it does provide some protection since pneumonia is often a complication of the flu. If you can avoid the flu, your chances of getting pneumonia are reduced. People in high-risk groups should also be vaccinated in addition to getting the flu vaccine.

There is a pneumonia vaccine for children (PCV13) that is given as part of the recommended childhood vaccinations in children under age two. It protects against 13 pneumococcal bacteria that are the most common causes of the illness in children.

Another pneumonia vaccine, PPSV23, is available for adults and children over age two as well and is recommended for people with chronic medical problems that put them at high risk and for all adults over the age of 65.

This vaccine protects against 23 types of pneumococcal pneumonia.

If you aren't sure if you need a pneumonia vaccine or not, talk to your health care provider. The PPSV23 vaccine is available for adults at many pharmacies as well.

What Does the Pneumonia Shot Do?

Although antibiotics such as penicillin were once very effective at treating pneumonia, the disease has mutated and many bacteria that cause it are becoming resistant to modern antibiotics. That is why it is so important to be vaccinated against this very serious disease.

Who Needs It and When?

Ask your doctor when the best time to be vaccinated is for you. Children under two should have a vaccination called Prevnar (PCV) four times before their second birthday to prevent serious illness from pneumonia. Usually, only one dose of the vaccine is necessary for adults. Anyone in the high-risk category should also have a pneumonia vaccine.

When Is a Second Dose of Pneumonia Vaccine Necessary?

Although most adults only need one dose of the pneumonia vaccine, some may need a second dose to be adequately protected. This includes:

  • A person over age 65 who had their first dose before age 65 and more than five years have passed since they received it
  • Anyone with a damaged or no spleen
  • Anyone with sickle cell disease or cancer
  • Anyone with HIV
  • Anyone with kidney failure or nephrotic syndrome
  • Anyone who has had an organ or bone marrow transplant
  • Anyone taking immunosuppressing drugs, such as long-term steroids or chemotherapy

When Should the Second Dose Be Given?

Anyone under age 10 that needs a second dose may receive it three years after their first dose. Anyone over age 10 that requires a second dose may receive it five years after their first dose.

Vaccine Side Effects

Side effects to the PPV are generally very mild; it is considered an extremely safe vaccine. However, common side effects do include:

  • Pain or redness at the injection site
  • Fever
  • Muscle aches

Severe allergic reactions are rarely reported, but it is a possibility that very serious problems, including death, can result from this vaccine, as with any medication. However, the risk of serious complications from the disease is much higher.

A Word From Verywell

Although pneumonia is a serious illness that can be life-threatening, most people who get it recover. It's important to pay attention to your symptoms and seek medical care when you need it. If you are having trouble breathing or it hurts to cough, contact your healthcare provider.

Your treatment plan will depend on which type of pneumonia you are diagnosed with, so be sure to follow your provider's advice and take any medications as prescribed. If you need to take antibiotics, take them all; don't stop taking them just because you feel better. That can mean that you only partially treat your infection and that the bacteria can develop resistance to the antibiotics.


Preventing Pneumonia. American Lung Association. Accessed July 17, 2016.

Vaccine Information Statement (VIS)." Pneumococcal Polysaccharide Vaccine - What You Need To Know. 29July1997. Department of Health and Human Services Centers For Disease Control and Prevention National Immunization Program. 27 Oct 2006 <>.

What Is Pneumonia? - NHLBI, NIH. Accessed July 17, 2016.

Wunderink RG, Waterer GW. Clinical practice. Community-acquired pneumonia. N Engl J Med. 2014;370(6):543-551. doi:10.1056/NEJMcp1214869.

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