If you’re like most people, you feel a lot better after getting a good night’s sleep. But for some people, staying up late and getting up early is just a way of life. Unfortunately, according to a new study from Seoul National University Boramae Medical Center in Seoul, South Korea, sleeping less than five hours (or more than nine hours) could be detrimental to your health.

The study, which was led by Professor Shim Hye-young, found that patients who slept less than five hours each night weren’t just at a high risk of being tired during the day - they also increased their risk of developing the painful joint condition temporomandibular joint disorder (or TMJ disorder for short).

When it comes to sleeping, there’s a lot of misinformation about what’s healthy and what’s not. But unfortunately, what you don’t know really can hurt you. Check out these three sleep-related myths and the real science behind them.

Sleep apnea is a serious condition that affects approximately 22 million people in the United States. It is categorized as the starting and stopping of breathing during sleep. Often, people with sleep apnea stop breathing for more than 10 seconds at a time, anywhere from five to 100 times an hour. Worse yet, because they are asleep, they don’t realize it's happening, making a bad situation potentially deadly.