Myths about sleep aren't just harmless old wives' tales. They can seriously undermine your health if they cause you to adopt poor sleep habits or discourage you from getting help for a sleep disorder. Yet misconceptions about sleep abound. In a recent study in Sleep Health, researchers compiled a list of questionable statements about sleep taken from press reports. Then they asked sleep experts to rate how false each statement was. These are the eight myths rated as most misleading. Myth 1: Your brain is inactive while you sleep. To an outside observer, it may look as if not much is happening while you snooze. But on the inside, your brain is abuzz with activity. Among other things, it's solidifying new memories, strengthening connections within the brain, and sometimes even creating fresh ideas. Myth 2: Being able to fall asleep anywhere means you're a great sleeper. In reality, dozing off anywhere, anytime could be a symptom of a sleep disorder, such as sleep apnea. Left untreated, sleep apnea increases your risk for a wide range of health problems, including heart attack, stroke, and type 2 diabetes. Be sure to get this symptom checked out. Myth 3: Many adults do fine on five or fewer hours of sleep. Individuals vary a bit in their sleep requirements. However, National Sleep Foundation guidelines stress that most adults need at least seven hours of sleep per night to be at their best. Myth 4: You can train your body to function just as well on less sleep. You may get used to operating on less sleep, but that doesn't mean you'll be firing on all cylinders. Chronically insufficient sleep has been linked to cardiovascular disease, diabetes, obesity, and depression. Myth 5: Your body doesn't care what time of day you sleep. It's better to snooze during the day than not at all. But night shift workers often have trouble falling asleep once they hit the sheets. That's likely due to disruption in their natural sleep-wake cycle, which is closely tied to light exposure. Myth 6: Lying quietly with your eyes closed is nearly as good as sleeping. Although they appear similar, sleeping and lying down while awake are very different states. If you don't doze off, you're missing out on changes in cognitive, cardiovascular, metabolic, and hormonal function that occur while you sleep. Myth 7: If you can't sleep, you should stay in bed and keep trying. That sounds admirably persistent, but it's counterproductive. If you don't fall asleep within 20 minutes, it's better to get out of bed and do something relaxing. Stay off your smartphone, tablet, and laptop, which emit blue light that stimulates alertness. When you get sleepy, return to bed. Myth 8: Loud snoring is annoying but harmless. In addition to disrupting your partner's sleep, frequent loud snoring may be a symptom of sleep apnea. So, don't brush it off as a mere nuisance. Discuss it with your doctor.