Doctors on Ukraine border say mental health is top medical priority

Doctors on Ukraine border say mental health is a top medical priority as refugees suffer from acute stress disorder.

Since the war in Ukraine began, more than 3 million refugees have fled -- by bus, train, car and foot -- for neighboring countries. Some have destinations in mind, while others have no plan. But as these displaced citizens navigate different yet equally impossible conditions, doctors at the countries that border Ukraine say there's a common thread: mental health is the most often reported medical problem.

Among the millions of refugees, acute stress disorder has been reported as a common ailment.

"Acute stress disorder is basically a fight-or-flight reaction that lasts a few days to a month and involves having been exposed to a threat to your life or limb and not being able to stop thinking about it," Dr. Craig Katz, a clinical professor of psychiatry, medical education, system design and global health at the Icahn School of Medicine at Mount Sinai, told ABC News.

In cases where people are in a fight-or-flight mode, "They're highly likely to have problems sleeping, being extremely anxious and not having much of an appetite, because they need to focus on survival," Katz said.