“Come inside or you’ll get pneumonia!” your mother may have yelled to you as you played outdoors on a cold or rainy day as a kid. While inclement weather itself doesn’t cause pneumonia, it is linked with respiratory infections, which are a major factor in the development of pneumonia, an infection that can affect one or both of the lungs.

What is pneumonia?

Pneumonia is a condition that occurs when germs—either a virus or bacteria—enter your lung(s) and cause inflammation in your air sacs. The sacs then fill with fluid, causing you to experience symptoms such as coughing, fever, and trouble breathing. Pneumonia can be very serious. About a million people in the U.S. are hospitalized for it every year, and more than 53,000 die from it.

How do you contract pneumonia?

There are many ways to contract pneumonia. According to the American Lung Association, about a third of all cases in the U.S. result from respiratory viruses, most commonly influenza (the flu). Bacteria also cause a significant percentage of pneumonia cases, most commonly pneumococcus (Streptococcus pneumonia). Less common bacterial causes include Legionella pneumophila (responsible for Legionnaire’s disease) and Staphylococcus aureus.

Who gets pneumonia?

Anyone can get pneumonia. However, some people are more likely than others to contract it. “Advanced age is a risk factor,” says Amar Safdar, MD, director of transplant infectious diseases at NYU Langone Medical Center in New York and associate professor of medicine at NYU School of Medicine. Being very young is also a risk factor, with children under five making up 70 percent of the population of children hospitalized for pneumonia in this country. (Worldwide, pneumonia is the single biggest killer of children under five, although these deaths tend to be concentrated in sub-Saharan Africa and South Asia.) Other risk factors for contracting the disease, according to Dr. Safdar, include chronic lung disease (including asthma), history of cigarette smoking, diabetes, heart disease, and anyone with suppressed immune function from conditions such as cancer, organ or bone marrow transplantation, or inadequately controlled HIV infection.

Who is at highest risk of hospitalization and/or death from pneumonia?

Because pneumonia has a multitude of potential causes, it may be difficult to determine exactly who is likely to be severely sickened. People with strains of bacteria that are resistant to antibiotics may have a particularly tough time. Dr. Safdar also cautions that certain underlying conditions present a higher risk to patients who contract pneumonia. “It’s not only the pathogen, it’s also who the host is,” he says, mentioning potential complicating factors such as chemotherapy, bone-marrow transplantation, and ventilator-assisted respiration.

How do I know if I have pneumonia?

Be alert to the following signs and symptoms of pneumonia:

  • fever that does not go down after a day
  • coughing with sputum (mucus)
  • chest pain
  • shortness of breath

It’s important to note that older and very young patients may only be lethargic and have loss of appetite.

Doctors may take swabs from your nose and throat in order to determine whether the infection is viral or bacteria. If it’s viral, such as influenza, it may be treated with an anti-viral medication like Tamiflu. Bacterial infections will be treated with antibiotics. A chest x-ray may be ordered in order to determine how much of the lung, or lungs, are involved.

Is there any way to avoid getting pneumonia?

“Prevention is really the key,” says Dr. Safdar. “Vaccination is the most effective way of reducing the risk of pneumonia.” A pneumococcal vaccine is recommended for children five years old or younger, people 65 or older, or anyone between six and 64 who is at increased risk due to an underlying condition. The annual flu vaccine, which can be given to babies as young as six months, is recommended for everyone.

Amar Safdar, MD reviewed this article.


Safdar, Amar, MD. Phone conversation with source on September 28, 2015.

“Pneumonia can be prevented—vaccines can help.” Centers for Disease Control and Prevention. Accessed on October 1, 2015.

”New CDC study highlights burden of pneumonia hospitalization on U.S. children.” Centers for Disease Control and Prevention. Accessed on October 1, 2015.

“Learn about pneumonia.” American Lung Association. Accessed on October 1, 2015.

”Pneumonia.” Cleveland Clinic. Accessed on October 1, 2015.