- Oh my God, is it really lack of sleep?

- Long-term lack of sleep.

(Bethany scoffs) But we're gonna combat that because we're gonna make sure all the babies out there watching are getting plenty of sleep.

- 'Cause all the babies, we know you're watching.

(cheerful music) - There's multiple reasons why 80 to 90% of teens in America are not getting the recommended eight to 10 hours of sleep per night.

- What?

That much?

That's like almost all teens aren't getting enough sleep.

- It's an alarming amount, and it's an issue because sleep deprivation in teens can lead to a ton of problems, from mood disorders, to anxiety, to stress, to trouble in school.

Long-term sleep deprivation is linked to a lot of chronic diseases.

- That's crazy.

- Not a good thing.

Teens, sometimes, aren't getting the same amount of sleep throughout the week.

In other words, they are very, very sleep deprived during the week and then say, "Oh, I can make up for my sleep over the weekend by sleeping for 13 hours."

When in reality, we have to have a consistent bedtime every single day.

- I didn't know that either.

I thought you could make up for sleep on the weekend.

- You cannot catch up on sleep deprivation.

Myth busted.

- So it's up to parents to enforce good sleep habits?

- It's up to a lot of factors, from parents to general awareness 'cause teens have to take a little bit of control their actions, to even school, and society in general to encourage teens to get more sleep.

But let me ask you a question about one thing that we can all change.

Do you use a screen before you go to bed?

- I do not.

- I'm actually impressed.

- There's no TV in our room even.

- I wish every teen would do this.

This is model sleep hygiene.

- Mm-hm.

- 'Cause here's the thing.

Most of the screens that we look at, this is a computer screen, your telephone, a tablet, emit blue wavelengths of light.

Now, right now, you're probably like "Science nerd, who cares?"

Here's the thing.

Blue wavelengths of light can block melatonin, which is a hormone secreted in our brain from the pineal gland, for anyone who wants to look it up.

- Is that what's the thing with the blue light?

It actually blocks?

- It blocks melatonin.

It usually starts to rise in our body before we go to bed.

It peaks in the middle of the night and is really responsible for making sure that our internal clocks are working and we're getting restful sleep.

And no one talks about the fact that blue wavelengths of light can disrupt melatonin and disrupt your REM sleep.

While any kinda light can suppress melatonin at night, blue light is the most powerful regulator of our sleep-wake cycle, or our circadian rhythm.

Pigments in our eyes are more sensitive to cool colors with short wavelengths like blue light, tricking our brain into thinking it's still daytime and thus, disrupting our natural circadian rhythm.

- What is the time period before sleep that doctors recommend no blue light?

What is the recommendation, and then what is realistic practice?

- Great question.

- Thank you.

- So in a perfect world, we say for at least one to two hours before your bedtime, and most of the teens I talk to openly tell me, "We have extracurricular activities, and then we have homework.

We have responsibilities.

We don't get to bed 'til very late."

This brings up a really important point because when we talk about teen sleep deprivation, we often point fingers at teens, right?

And I say, "Get off the computer or stop playing video games."

Truth be told, some teens aren't getting enough sleep because they have to work another job after school or they have to commute a really long way home from high school or they have family responsibilities.

So there also is this massive disparity in society, which also contributes to sleep deprivation.

- How many hours of sleep should a kid really be getting?

- Textbook to answer, but those really, really young babies, zero to three months, obviously, need a ton of sleep, about 14 to 17 hours a day.

That's gonna involve some napping because your child should not be sleeping that much in one stretch.

But then as kids go through adolescence into grade school, they're gonna need a little bit more less sleep as time goes on until the time they're teenagers, about eight to 10 hours of sleep is recommended.

- When should kids stop napping?

My answer is never.

What's your answer?

- My answer is, again, look at how much sleep they're getting overnight.

Naps cannot replace a full night of sleep.

So if you have a growing child and they're getting a bunch of naps, but then they have fragmented, broken sleep at night, you can't add all the naps together and say, "We're good, it's still 12 hours."

But obviously, in newborn babies who need upwards of 17 hours of sleep, they're gonna do that through a bunch of different naps because, well, you know better than I do, they're gonna wake up a bunch because they wanna eat.

- Okay.

I guess what I'm trying to get you to do is say that napping is mandatory so I can tell my kids they have to nap.

"Dr. Alok said you have to nap.

Nap now."

- I can't tell them it's- - "Four out of five doctors say nap."

- Your children are a little bit older.

- Just say it.

It's okay.

They're a little bit older, so I can't say it's mandatory to nap.

Here's the thing.

In the United States, we see a lot of napping start to stop around the time kids are in kindergarten and first grade.

- [Bethany] Okay.

- So when it comes to talking about ways to improve sleep, it's a multifaceted approach in creating the optimal sleep environment.

- [Bethany] So I know it should be cool, have a period of winding down.

- You nailed it.

Cool environment, dark, kind of reducing all the stimulus, creating an established bedtime routine, and then other things that we can work on as children get older and for us, is reducing the blue light around us, and older people can avoid taking stimulants before bed, no coffee.

What you do wanna do is do something that is less stimulating, like read a book, go to bed at a consistent time, and don't ignore the signs that you're tired.

If you're sleepy, go to bed.

- The baby's just typing away, going, "What is my mom trying to find out about me?"

(simulates keyboard clicking) "What's she looking for?"

(simulates keyboard clicking) - Baby sounds like a rodent.

- That's a baby typing.

- Baby rodent?

(both simulate keyboard clicking) (bright music) (gentle music)