Who gets it
Sleep problems from shift work affect male and female workers of all age groups. Those who have unusual work hours are most likely to have it.
Estimates are that 2% to 5% of the general population is affected. This estimate does not include people who work early-morning shifts.
Some people feel that they function better at night. They go to bed very late at night on a regular basis. They may have delayed sleep phase disorder.
These people may choose to work a night shift. They prefer to work during the late hours when they feel that they are more alert.