It’s a simple but unfortunate fact that most of us don’t sleep enough. If you’re short on Zzzzs, factors like stress, a hectic schedule or even a health concern could be chipping away at the slumber your body and mind need to function at their very best. But putting stock in some common sleep myths can prevent you from getting quality rest, too. Reset your expectations and beliefs: These five truths shed light on why you don’t need to settle for less when it comes to this important aspect of your health and how some habits may be keeping you wide-eyed.

Getting older doesn’t mean that you need less sleep.

You may have found it easier to sleep when you were younger. As years pass, your body produces less melatonin, the hormone that helps set your circadian rhythm into snooze mode. Exposure to small amounts of light, such as alarm clocks, smart phones and other devices, offset that pattern; pain from arthritis or another health issue may disrupt sleep that used to be sound; your mind may keep you alert as it races with thoughts of family responsibilities or financial stressors. Despite what you think you can “get by” on, most adults need seven and a half to eight hours of nightly rest for optimal health—regardless of age. You’ll know you’re getting enough sleep when you don’t need an alarm to wake up, and when you do wake up, you feel rested, refreshed and energetic throughout the day. Instead of accepting the five or six you manage to clock, work to identify the cause of your lack of sleep and address it. Supplement your total sleep time, if necessary with naps.

Though you may think you can function on less sleep, that doesn’t mean you should.

Sure, maybe you can make it through the day on a few hours of rest, but how well? Sleep deprivation makes it harder to pay attention, solve problems, make sound judgments and commit things to memory. It can zap your energy, contribute to moodiness and even increase your risk of an accident. Not to be forgotten, a lack of sleep may even increase your risk of heart attack, stroke, high blood pressure, atrial fibrillation and diabetes. Plus, research shows that less snooze time raises ghrelin levels—a hormone that stimulates your appetite—and can increase your insulin resistance. “Getting by” suddenly doesn’t seem like quite enough when you consider that you may be jeopardizing your performance, relationships, happiness, safety and longevity in the process.

A good night’s sleep is important—but stressing about it won’t do any good.

A key finding about those who sleep well is that they don’t worry if they occasionally wake up. The more anxious you get about falling or staying asleep, the harder it can be to settle your body and mind so you can nod off. While you may need to get up to urinate, you may be able to avoid other stirring by keeping light and sound to a minimum, replacing a lumpy mattress, avoiding drinking caffeinated or alcoholic beverages before bedtime.

Lying in bed when tossing and turning won’t help you nod off.

It’s recommended to get out of bed if you’re unable to drift off after 20 minutes, however, it’s important to seek out something peaceful and relaxing, such as reading with a soft light, gentle yoga or mindful breathing. Exposure to bright or intense lights, like computer monitors and TVs, are discouraged as these can activate the brain. When you’re beginning to feel drowsy, head back to bed.

Exercise could be negatively affecting your sleep.

It’s true that a workout may make it easy to melt into your mattress. In fact, Oregon State University researchers found that people who exercise 150 minutes a week improve their quality of sleep by 65 percent. But activity also raises your body temperature, which can take as long as six hours to return to normal. Because your body finds it easier to fall asleep when it’s cooler, it may be wise to get exercise at least three hours before you turn in. Or try some calming yoga postures, like Child’s Pose or Reclining Butterfly, to help relax you before bed.