National Guard soldiers may be plagued with sleep problems when they return home from the battlefield, according to a small study, reports Newsmax.

For the new analysis, published online in Sleep Health, researchers first surveyed 928 veterans on National Guard bases in Hawaii and New Mexico who had been deployed to Iraq, Afghanistan, Somalia or other war zones. More than 90 percent were male.

More than half of them reported some degree of sleep problems after returning home, including trouble falling or staying asleep followed by feeling irritable or having angry outbursts.

Researchers then identified a subset of 101 veterans who had symptoms associated with posttraumatic stress disorder or substance use disorders and interviewed them face-to-face. In this group, the rate of sleep problems after deployment was 81 percent.