But what about the other end of the spectrum: sleeping too much? Is it possible that oversleeping can have negative health impacts too, and is it a sign of something else if you’re getting the recommended seven to nine hours a night and still feeling tired? Here’s what the experts say. On the other hand, if excessive sleeping becomes a habit, that’s where it also becomes a problem. Oversleeping—just like overdoing other things like eating too much sugar orover-exercising—can be harmful, says Michael Grandner, PhD, MTR, CBSM, FAASM, director of the Sleep and Health Research Program at University of Arizona College of Medicine, Tucson, and sleep advisor for Casper. What’s more, sleeping too much could lead to a shortened lifespan." There is now [more than] 50 years of data showing that people who get excessive sleep—nine to 10 or more hours per day—have a shorter lifespan, in addition to people who get insufficient sleep also having a shorter lifespan," Grandner says. “The data on long sleep is even stronger than short sleep.” He adds that long sleepers are more likely to have chronic diseases such as obesity, hypertension, diabetes, fatigue, and systemic inflammation. Long sleepers who never feel rested can also look into doing a sleep study to get to the root of the problem, says Moe. Some sleep disorders can exist without you even knowing—such as narcolepsy or idiopathic hypersomnia (a chronic neurological disorder marked by an insatiable need to sleep)—and talking with your doctor or participating in a sleep study can help uncover these disorders. “There are ways we can help treat them so you can function in society with more ease,” Moe adds. The bottom line is that whether you’re sleeping too little or too much, finding a way to get the right amount of sleep is crucial. Find that ideal sleeping time that works best for you; stick to it as much as possible; and you’re on track for a healthier lifestyle. “Good sleep typically makes our bodies healthier,” says Dr. Majestic, “and it makes us all feel and look better.” RELATED: 11 Healthy Habits That Can Actually Help You Sleep Better