The stress and chaos patients experience in the hospital may make them prone to a new illness — and landing back in the hospital. Nearly one in five seniors discharged from the hospital will be re-admitted within 30 days with a completely different ailment from the one that originally landed them in a hospital bed, according to a report published in the New England Journal of Medicine.

The phenomenon has even been given a name: post-hospital syndrome.

The point of the new report “is not to trash hospitals,” says the author Dr. Harlan Krumholz, a cardiologist and a professor of medicine at the Yale School of Medicine. “But, it’s to say maybe we haven’t adequately recognized the potential toxicities that can occur during the course of a hospital stay.”

After a hospital stay, patients are often weak from lack of exercise, sleep deprivation or malnutrition. The first 30 days after discharge “are a transient period when the patient is at great risk and is susceptible to many things,” according to Krumholz, but patients are rarely informed how to take care of themselves.

After scrutinizing Medicare data, Krumholz found that the majority of patients being readmitted to the hospital had a different illness from their original diagnosis. Someone who had been treated for pneumonia might be back in the hospital with an infection, heart failure or wounds from a car accident or fall, for example.

“We tend to be in battlefield mode fighting the acute cause of admission,” Krumholz says. “And everything else is pushed to the side while we focus on that issue to the potential detriment of the patient’s overall well-being. Sleep, doesn’t matter when we’re dealing with your pneumonia.”

At a minimum, patients need counseling, Krumholz says. They might be warned, for example, that they’ll be a little foggy for the next few weeks, “so don’t drive a car and don’t make any important decisions,” he explains.

Along with that, hospitals need to make a greater effort to respect patients’ sleep schedules and to get them moving as soon as possible so they don’t lose so much muscle tone.

Not everyone agrees with Krumholz’s diagnosis. While being in the hospital is stressful and can contribute to a delay in recovery, Dr. Mark Williams, a professor and chief of the division of hospital medicine at Northwestern University’s Feinberg School of Medicine acknowledges counters that the study “doesn’t seem to recognize the good that has been done for the patient.”

Still, Williams says, researchers should look for ways to better prepare patients for discharge. Visit NBC News for the article.