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PITTSBURGH (KDKA) – Cough, fever, trouble breathing, symptoms of the lung infection, pneumonia.

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“It can be serious. Patients can get very sick, and require hospitalization for pneumonia,” says AGH internal medicine physician Dr. Marc Itskowitz.

Every year, there are more than 3-million cases in the United States.

“Usually with pneumonia, you have to have antibiotics, and in some cases, you have to come into the hospital,” he explains.

In fact, about a million people a year are hospitalized for this.

“It’s the fifth leading cause of death, it’s the number one infectious cause of death in the United States,” says Dr. Itskowitz.

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Washing hands, avoiding sick people, and getting a flu shot are ways to prevent pneumonia. About 20 to 40 percent of cases are because of viruses.

The very old and very young, having lung disease already, and smoking are risk factors. But anyone can get it.

“Sometimes we’ll see it in a healthy patient under periods of stress, if they’re not sleeping well, if they’re not eating well,” Dr. Itskowitz says.

To help with diagnosis, your doctor may check a blood count and a chest x-ray. Normally, the lungs should appear black, because air on x-ray looks black. With pneumonia, portions will appear white.

Often in the fall and winter, there is a spike in the number of cases. But there has been no significant increase in this doctor’s practice or in the hospital.

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“We always see pneumonia this time of year, I just haven’t seen what I would consider an unusual or alarming amount in the last couple weeks,” Dr. Itskowitz says.