What to Know About Walking Pneumonia

You’re probably very familiar by now with the most common respiratory illnesses that can cause winter misery: cold, flu, COVID-19, and RSV. But the U.S. Centers for Disease Control and Prevention (CDC) reports that cases of another illness are also on the rise.

Walking pneumonia has been steadily infecting more people since last spring, says the agency, with younger children accounting for the most cases. That’s unusual, since most walking pneumonia cases typically occur in school-aged children and older adults. But there is no formal national reporting system for walking pneumonia, so the CDC can only estimate, based on testing data from emergency rooms, that about two million cases occur in the U.S. each year. The latest data from one company’s testing information shows that positive tests for walking pneumonia have increased from 0.7% to 3.3% since last spring for people of all ages.

Cases of walking pneumonia usually follow a pattern: they surge every three to seven years, likely because waves of infections help people generate antibodies against the bacteria, which provide protection for a while. The recent uptick in cases may be due in part because “we are probably at the end of that cycle,” says Dr. Panagis Galiatsatos, associate professor of medicine at Johns Hopkins Hospital and a spokesperson for the American Lung Association. “And it’s likely also brought on by the [general] drop in antibodies during the pandemic—so we’re due, timing-wise.”

Here’s what experts say to know about the illness.

What is walking pneumonia?

Walking pneumonia is a milder form of pneumonia—sharing symptoms including fever, sore throat, and fatigue—and it gets its name because the symptoms often aren’t severe enough to keep people in bed or send them to the hospital. “You don’t feel real well, you’re slowed down, a little short of breath and have a cough that may be annoying,” says Dr. Teresa Lovins, a family physician who owns her own private practice in Indiana and serves on the board of directors of the American Academy of Family Physicians. “But you can keep doing the things you want to do with walking pneumonia.”

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Walking pneumonia differs from other respiratory infections like flu or cold because it quickly settles in the chest and can leave people feeling short of breath. With walking pneumonia, any congestion may be short-lived and last less than 24 hours, says Lovins.

What causes walking pneumonia?

Both pneumonia and walking pneumonia are infections of the lung tissue, and both can be caused by a number of different viruses or bacteria. Walking pneumonia is most often caused by mycoplasma pneumoniae bacteria, while pneumonia can be caused by bacteria like streptococcus pneumoniae, hemophilus influenzae, Legionella pneumophila, or viruses such as influenza, the cold virus, or RSV.

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How do I know if I have it?

Doctors can test for the bacterium M. pneumoniae or can order a chest X-ray to make a diagnosis. Emergency departments and urgent care centers can test for the bacterium, but most primary care physicians rely on their expertise in listening to patient’s lungs to make the diagnosis. “There is a different sound the doctor is listening for when we listen to the chest for pneumonia,” says Lovins. “There is a test for mycoplasma, but it’s not typically done in the family physician’s office; it’s the exam that gives [walking pneumonia] away a lot of the time.”

If you have a cough that hasn’t resolved in a week, or are still feeling run down after getting sick and improving, then it’s probably worth seeing a doctor to figure out if you might have walking pneumonia.

You can’t test yourself at home for the bacterium yet, but kits for M. pneumoniae will likely be developed in coming years, says Galiatsatos.

Is there a treatment for walking pneumonia?

The right antibiotic can treat walking pneumonia, which is why some doctors say testing is important although it’s not always available. “It’s important to test for M. pneumoniae because what doctors are likely to do, especially if they think you have pneumonia, is to grab the most aggressive antibiotics, like penicillin or fluoroquinalones,” says Galiatsatos. “But people take them and still don’t feel well. That’s because mycoplasma isn’t affected by these common antibiotics. Mycoplasma needs azithromycin. It’s often seen as a wimpy antibiotic, but it does the trick.”

How can I protect myself from getting it?

The same advice that doctors give for the prevention of any respiratory disease also applies here: avoid crowded indoor settings with poor ventilation to the extent possible, and if you have to be in one, consider wearing a mask. Wash your hands often, and if you develop symptoms like sneezing and coughing, cover your mouth to limit the chances you’ll spread anything to others.