Working overnight causes “chaos” in the body and could lead to long-term damage, BBC News reported.

In a study published in Proceedings of the National Academy of Sciences, researchers found that subjects who went from a normal sleep pattern to that of a night-shift worker experienced changes at the molecular level.

Researchers reported that 6 percent of genes are precisely timed to function at specific times of the day. Working the night-shift seemed to throw off that genetic fine-tuning, which may explain why people experience everything from changes in body temperature to decreased athletic ability when they are thrown off their sleep schedule.

"It's chrono-chaos. It's like living in a house. There's a clock in every room in the house and in all of those rooms those clocks are now disrupted, which of course leads to chaos in the household,” study author Derk-Jan Dijk, of the University of Surrey, told BBC News.

Previous research has shown too little sleep at the wrong time of day has been linked to an increased risk of Type 2 diabetes and obesity and some research has also found that heart attacks are more common in night workers.

The changes in rhythmic patterns of gene expression may be related to these long-term health consequences, researcher said.

Click for more from BBC News.