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Family Health

Walking Pneumonia: What You Should Know

BY CARRIE MACMILLAN February 22, 2024

Yale Medicine doctors discuss the common lung infection.

Not all medical conditions have names that spell out their meaning, but “walking pneumonia” seems to be an exception.

Walking pneumonia is a nonmedical term for a mild form of pneumonia. While a more typical case of pneumonia might send you to bed—or even the hospital—with walking pneumonia, you can usually go about your everyday activities, even though you likely have symptoms, including cough, fatigue, and, sometimes, fever.

“It’s more of a colloquial term than an exact medical diagnosis,” explains Matthew Ellman, MD, a Yale Medicine primary care physician.

Thomas Murray, MD, PhD, a Yale Medicine pediatric infectious diseases specialist, describes a typical patient with walking pneumonia as having a cough and some mild breathing difficulties that last longer than the standard three to five days of an acute respiratory infection, such as the common cold. “It isn’t severe enough that it incapacitates you, but it lingers and can make you feel uncomfortable,” he adds.

Even though walking pneumonia isn’t usually serious, you should contact your doctor if you are experiencing worrisome symptoms or if a cold lasts more than five days, the doctors advise.

Below, Drs. Ellman and Murray talk more about walking pneumonia, including how it is diagnosed and treated.

What causes walking pneumonia?

Pneumonia is caused by various microorganisms, usually bacteria and viruses. The infection usually starts after one of these microorganisms is inhaled from the upper airways into one or both lungs. There, the infection causes the air sacs, or alveoli, to fill with pus or fluid.

Broadly speaking, pneumonia falls into two categories: community-acquired and hospital-acquired, the latter of which is considered more dangerous, as this type is more likely to be resistant to antibiotics.

Walking pneumonia is a common subtype of community-acquired pneumonia, and is typically caused by a difficult-to-detect bacterium called Mycoplasma pneumoniae. Infections caused by this bacteria are generally mild but can sometimes be severe.

There are a few different ways one can get a bacterial infection, Dr. Murray explains. “In many cases, it can happen with bacteria you are colonized with. In other words, it's already part of your upper respiratory tract. It lives in your nose or the back of your throat. When you get sick with a virus, it allows the bacteria to get into your lower lung and cause disease,” he says. “Say, for example, you’ve had the flu—that increases your risk for pneumonia afterward.”

And because winter is virus season, many respiratory viruses—including respiratory syncytial virus (RSV)—can travel from the upper respiratory tract to the lungs and cause pneumonia, Dr. Murray notes.

Pneumonia can also spread when an infected individual coughs or sneezes, and someone else breathes in those respiratory droplets. It occurs most often in crowded settings, including schools, college dormitories, and military training sites.

However, those who spend a short amount of time with someone who has a mycoplasma infection do not usually get sick, the CDC says.

“In general, any type of pneumonia, particularly if it’s bacterial, is less contagious than the viruses that cause colds, flu, or COVID,” Dr. Ellman says.

How is walking pneumonia diagnosed?

Walking pneumonia is sometimes called an “atypical” pneumonia—a term used to describe pneumonia caused by bacteria that is difficult to detect through standard bacterial cultures.

“There are blood tests that don’t work very well. There are also swabs, just like you do for COVID, to check for mycoplasma, the bacteria often associated with walking pneumonia. But not every lab does those, so they’re not easy to get,” Dr. Murray says. “And if it’s negative, it doesn’t mean you don’t have it, because you can still have symptoms after it goes away from your upper respiratory tract.”

Therefore, walking pneumonia is often diagnosed by a physical exam and possibly an X-ray, Dr. Murray says. It can sometimes be hard to tell the difference between a more typical case of pneumonia and walking pneumonia, he adds.

“One of the ways you can differentiate it is with a chest X-ray. A more typical pneumonia would be called ‘lobar pneumonia,’ meaning you can see that one part of the lung is infected on the X-ray,” he says. “Walking pneumonia will look patchy on the X-ray. There isn’t just one part of the lung involved; it’s more spread throughout.”

How is walking pneumonia treated?

While many community-acquired cases of pneumonia caused by bacteria are treated with antibiotics, the most prescribed ones, such as amoxicillin, don’t always work for mycoplasma pneumonia, Dr. Murray says. But certain antibiotics, such as azithromycin, work well, so it’s important to get the proper diagnosis, he says.

“The good news is that this type of pneumonia does not tend to be serious in healthy people, and most do very well with treatment,” he says.

If the pneumonia is believed to be caused by a virus, antibiotics won’t help. In fact, for children under 2 years of age, the majority of cold and lung infections are viral. Instead, those patients should rest, drink plenty of fluids, and, if needed, use over-the-counter medications, such as acetaminophen or ibuprofen, for discomfort.

There are potential treatments for influenza, such as Tamiflu, and COVID-19, such as Paxlovid, depending on your age and underlying risk factors for complications, adds Dr. Murray.

Are there vaccines for walking pneumonia?

Certain types of pneumonia have vaccines to protect against them and are recommended for children and older adults, “but there isn’t a shot that covers walking pneumonia,” Dr. Murray says.

“Still, it’s good to stay up to date on all recommended vaccines—including those for RSV, flu, COVID, and pneumonia caused by a common bacteria called streptococcus,” Dr. Ellman says. “All of these can help reduce the risk of getting pneumonia.”

When should you contact your doctor?

While most cases of walking pneumonia aren’t dangerous, it’s important to pay attention to your symptoms, particularly if you develop new problems after seemingly recovering from another illness, such as the flu.

“Say you have the flu and you start to feel better, but then you begin to feel sick again—it’s more difficult to breathe, and the fever comes back. Although it’s not that common, it could be a community-acquired pneumonia setting in that requires an antibiotic,” Dr. Murray says. “That would be a great reason to reach out to your primary care doctor.”

Another reason to pay attention to symptoms that aren’t resolving is that walking pneumonia can turn into a more serious form of pneumonia if left untreated. Each year, 4 to 5 million people in the United States get pneumonia (not including pneumonia caused by COVID-19), and about 55,000 people die from it.

“Pneumonia is a common cause of hospitalization, and it can be life-threatening. It can cause organ damage and be complicated by cardiac and kidney problems, as well as cause permanent damage to the lungs,” Dr. Ellman says. “Because walking pneumonia can become a more serious case of pneumonia, it’s important to be in touch with your doctor.”