What’s wrong in this picture? Gastrointestinal and digestive problems such as indigestion, heartburn, stomach-ache and loss of appetite are more common among rotating shift workers and night workers than among day workers. It is less clear if more serious conditions such as peptic ulcers are more common in shift workers. The irregular work, sleep and eating schedules are not helpful for the proper care of ulcers.

According to the National Sleep Foundation, a shift worker is not just someone who works nights, but anyone who works outside a steady 9 to 5 schedule.

The millions of shift workers in the U.S. include police officers, firefighters, nurses, doctors, pilots, waitresses, truck drivers, and many more professionals. Even a personal trainer who works out at the gym with clients in the early mornings and evenings is a shift worker.

As shift work has become more widespread in the U.S., the health risks have become a focus both for researchers and for the businesses that employ shift workers.

The general message from the experts is that getting enough good-quality sleep and minimizing disruption to the body’s circadian rhythms are the best ways for shift workers to stay healthy.