Why is sleep important for memory?

Because sleep is when your brain stores the day's impressions. It goes back over what you've experienced and learned and helps turn it into long-term memories. The CDC recommends 7 to 8 hours of sleep a night for adults over 65, and too little sleep makes it harder to concentrate and remember.

Sleep feels like a break, but for your brain the night is working time. That's when the day's impressions get sorted and the important things get stored.

What happens while you sleep

Researchers have found that during sleep, the brain reactivates what you experienced and learned during the day, and that this helps lock it into memory. The US National Heart, Lung, and Blood Institute puts it simply: sleep helps with learning and with forming long-term memories. New things stick better after a night's sleep.

It works the other way too. When you don't get enough sleep, it's harder to concentrate, think clearly and remember things, and the National Institute on Aging lists memory problems among the effects of poor sleep.

Sleep changes with age

Many older adults find their sleep gets lighter and shorter: they go to bed and wake up earlier, and they wake more often during the night. The National Institute on Aging describes these as normal changes with age. The CDC recommends 7 to 8 hours of sleep a night for adults 65 and older, while the National Institute on Aging puts it at 7 to 9 hours.

What matters most is how you feel during the day. If you feel reasonably rested and alert, that's a good sign, whatever the number says.

Tips for better sleep

US health agencies recommend a few simple habits:

• Go to bed and get up at the same times every day.
• Keep the bedroom dark, quiet and at a cool, comfortable temperature.
• Avoid caffeine late in the day, and alcohol before bed.
• If you can't sleep, get up and do something calm, like reading, until you feel tired, rather than lying there awake.
• Get regular exercise, but not in the last three hours before bed.

When to talk to your doctor

Sleep problems that last for weeks, heavy snoring with pauses in your breathing, or real tiredness during the day despite a reasonable night's sleep are worth mentioning to your doctor. According to the National Institute on Aging, sleep problems like insomnia and sleep apnea become more common with age, and both can be treated. Since sleep and memory are closely linked, good sleep is one of the most concrete things you can do for your brain.

This is general information, not medical advice. Every situation is different, so talk to a doctor about yours.