For the first time last year, older adults got their very own personalized sleep recommendations. The National Sleep Foundation concluded, after reviewing the scientific research on sleep duration, that adults 65 and up should aim for 7 to 8 hours a night, compared to adults 26 to 64, who should sleep between 7 and 9. The distinction might not seem like a huge deal at first, but it's a nod to what many older adults inherently know to be true: Sleep really does change with age. (Worried about your memory? Check out these natural solutions for an age-proof brain!)

"Our sleep changes throughout the lifespan," said Natalie D. Dautovich, PhD, the NSF's environmental scholar and an assistant psychology professor at Virginia Commonwealth University.

Some of the most dramatic changes, she said, actually occur in our 20s, but as we reach older adulthood some themes tend to arise. Many 50+ sleepers find it's easier to become awakened during the night, which is reflected in a little shorter sleep duration over all, Dautovich said. 

It's not exactly a welcome change: The NSF found 71 percent of 55- to 64-year-olds report some sleep problem, including difficulty falling asleep, waking up still tired, or snoring.

Dautovich urges anyone dealing with these issues to bring them up a medical professional. Depending on your symptoms—maybe you're excessively sleepy during the day or you're irritable, unfocused, and achy—medication, lifestyle changes, or even cognitive therapy can help.

Here are a few of the unique sleep situations facing you as you age.

Your bedtime and your wake-up time shift earlier.
Remember how all you wanted to do when you were 19 was stay up late and doze until noon? You weren't just exercising your laziest teenager muscles; our natural internal clocks, technically called our circadian rhythms, are delayed until our 20s, meaning we truly don't get tired until later at night and don't feel alert until later in the morning, Dautovich explained. After we grow out of this phase, though, our circadian rhythms keep advancing, and later in life we tend to become sleepy earlier and feel our most alert earlier in the morning, too. (Fake a good night’s sleep with these 7 essential eye-makeup tips for women over 40.)

You wake up more during the night.
An odd thing starts to happen in our brains as we age, says board-certified sleep specialist and sleep doctor, Michael J. Breus, PhD. 

"The amplitude of our brain waves changes," he said.

To be classified as deep, restful, restorative sleep, brain waves have to reach a certain height, and after age 50 or so, the spikes simply don't get as high, he says. That lighter sleep is a heck of a lot easier to disturb, meaning you become a lot easier to wake up. Whether it's your bed partner's snoring, the usual creaky house noises, or a little indigestion, you may find you're no longer able to sleep right through disturbances. Those arousals in turn mean you're getting worse sleep, Breus said.

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Of course, it's only natural to figure you can make up for that with an afternoon nap. A word of caution, though: While you're undoubtedly tired during the day if you've tossed and turned all night, napping can sometimes do more harm than good.

"Unfortunately, that can disrupt our natural rhythms and result in poorer sleep the following night," Dautovich said.

You gotta go.
Some 53 percent of adults ages 55 to 84 get up to pee every night or almost every night, according to the NSF. Certainly, some of us get a more frequent urge to relieve ourselves as we age, possibly because our nerves don't function as well. But hitting the head may also be related to that lighter sleep we get, she said. "People are more aware of urges to urinate that they may not have been aware of when they were in deeper sleep."

As long as you can fall back to sleep within 5 or 10 minutes of a pee break, don't stress. If it's difficult to doze off again after a trip to the loo, bring it up with your doc. (Can’t poop? These 10 foods will take care of that!)

Your hot flashes never quit.
Menopause's famed hormonal wackiness can definitely disrupt your slumber, Dautovich said. Fluctuations in estrogen and progesterone can make healthy sleep harder to come by, and insufferable hot flashes can wake some women up or make it impossible to drift off. Mood changes can also trigger sleep problems, making menopause decidedly unfriendly to sleep. Aside from following all the general sleep hygiene rules, Dautovich suggested making your sleep environment more "flexible" if you can: Sleep in breathable fabrics and layer sheets and blankets on the bed so you can easily fling 'em to the side mid-flash.

You start to snore.
One of aging's more unpleasant side effects is how easy it is to suddenly find yourself carrying a bit of extra poundage. (Take those pounds off with these 8 weight loss secrets no one but nutritionists know.)

That weight gain can lead to snoring, because a thicker neck means a narrower windpipe, Breus explained. If your windpipe narrows so much it becomes blocked, you may even stop breathing periodically throughout the night, known as obstructive sleep apnea. While sleep apnea is more common in men, he says, after menopause many more women start to experience it, too. If you're snoring or have apnea, you don't get as much air in, Breus said, which changes the overall quality of sleep. Of course, you're also likely bothering the person lying next to you.

"If you sleep next to a snoring bed partner, you lose approximately 1 hour of sleep a night," he said. (Separate bedrooms suddenly doesn't seem so outlandish...)

You're at a higher risk for restless legs.
The rates of this mysterious sleep-related condition start to climb after people hit 50 or so, Breus said. The overpowering urge to move, usually the legs, can also grow more severe with age. Although there's still a lot experts don't totally understand about restless legs syndrome, it's thought to be related to the brain chemical dopamine, which declines with age, or iron deficiency, also common among older folks. 

This article originally appeared on Prevention.com.