After a busy work week, many people look forward to the weekend for the chance to sleep in. But those extra snooze hours could lead to some serious health issues, according to a new study.

Researchers from the Sleep and Health Research Program used data from the Sleep and Healthy Activity, Diet, Environment, and Socialization experiment to explore how sleep irregularity affects the body.

They assessed the survey responses from 984 adults between the ages of 22 and 60 to determine which participants had experienced social jet lag, which occurs when you go to bed and wake up later on weekends than during the week, and other conditions such as insomnia, cardiovascular disease, fatigue, and sleepiness.

Scientists discovered that 85 percent of people wake up later on the weekends, and they have linked the pattern to terrible moods and chronic fatigue.

Analysts also revealed that the condition could increase the risk of heart disease, with each additional hour of social jet lag raising the chances by 11 percent.

"These results indicate that sleep regularity, beyond sleep duration alone, plays a significant role in our health," lead author Sierra B. Forbush told EurekAlert. "This suggests that a regular sleep schedule may be an effective, relatively simple, and inexpensive preventative treatment for heart disease as well as many other health problems."

A 2012 study found the average cost of heart disease in adults is more than $4,200, according to Monyish.com

Want to lower your risk? Doctors recommend sleeping seven hours each night and to fight the urge to catch some more z’s during your time off.