Everybody sleeps,

but not all of us know how important sleep is.

Hi, I'm Ravi Aysola,

and I'm a professor of clinical sleep medicine at UCLA.

Today I'm gonna debunk some myths about sleep,

so we can all work on getting a better night's sleep.

[dramatic music]

Our limbs are paralyzed during REM sleep.

That is not a myth, that is true.

There's circuitry within the brain,

especially during REM sleep,

that actually inhibits our skeletal muscle tone.

This is so we don't act out what we're dreaming about,

and accidentally hurt ourselves.

REM sleep, or rapid eye movement sleep,

which is about 20% of the total time we sleep,

is a unique neurologic and physiologic state.

Our eyes are moving rapidly during that time,

while the rest of our body's muscles

are almost in paralyzed state,

except for the breathing and eye muscles.

It's when we tend to dream,

it's also when our brains are very active.

You may have woken up sometimes from a nap,

or if you were particularly sleep-deprived,

feeling like your mind is awake,

but you can't move your body,

that's sleep paralysis.

It can be really scary,

but it's not dangerous.

It can happen in people

who've just been chronically sleep-deprived,

or it may be a sign of a sleep disorder.

Some disorders of sleep,

especially REM sleep,

can result in inappropriate muscle inhibition and paralysis.

During wakefulness, people with narcolepsy,

which is a disorder of sleep-wake regulation in the brain,

can actually experience what we refer to as cataplexy.

This can occur when they're surprised,

excited,

or laughing,

and can result in them collapsing to the ground even,

in its extreme cases.

We have animals that do this as well.

Certain breeds of dogs experience cataplexy,

and when they get excited,

they may actually collapse.

We only sleep with our eyes shut.

That's actually a myth.

Some people may have their eyes partially open during sleep.

This can happen in people who are experiencing eye problems,

or other medical problems that affect the eye.

It can also happen in people who are really sleep-deprived.

Our brains have the ability to have microsleeps,

when we go to sleep for very brief periods of time,

and aren't even aware of it.

This especially happens if we're sleep-deprived,

and can happen with our eyes open.

Having hemispheric sleep is adaptive for an aquatic mammal,

because it makes sure

that they still are able to go up to the surface to breathe,

as well as be aware of predators.

There's some data that suggests

that humans may experience regional sleep.

This may be times where our eyes are open,

but we're not really registering what's going on,

because parts of our brain are not fully awake,

especially if we're sleep-deprived.

Everyone needs seven hours of sleep.

That's a myth.

The reason you often hear that seven hours of sleep

is the magic number of hours of sleep we need,

is based on a large number of studies

that have looked at populations,

and doesn't necessarily mean

that every individual needs exactly seven hours.

Some people need less.

Some people may need more.

The important thing is not just how much sleep,

but it's the quality of sleep,

and how you feel after you've slept.

Chronic insufficient sleep,

less than seven hours a night,

and especially less than six hours a night,

is associated with an increased risk of obesity,

diabetes,

cardiovascular disease,

and mood disorders like depression and anxiety.

How much we sleep,

and when we sleep,

changes over our lifespan.

Parents often complain about their lazy teenagers,

that they can't get up in the morning and get to school.

During adolescence, this is physiologic and normal.

Now that we've recognized that wanting to stay up later

and wake up later, is normal for teens,

a number of states have implemented policies

to delay school start times for teens.

You can catch up on lost sleep.

That's true,

but it's really important when you catch up on that sleep,

and how you catch up on that sleep.

Sleep deprivation is bad for you,

both in the short term and the long term.

Acute sleep deprivation can have negative effects

on everything from your mood,

your appetite,

as well as your cognitive performance.

Sleep debt is not getting enough sleep

that our bodies and brains need over a long period of time.

We can pay that debt back, to a degree.

What's critical is when we pay that sleep debt back.

One way to do this is to take a power nap.

I think the best time to take a nap

is in the early afternoon,

sometime between one and four, for most people.

It's a natural dip in our circadian rhythms,

when we tend to be a little bit more sleepy

during the 24-hour day.

Circadian rhythms are 24-hour biologic rhythms

that we have developed over time.

Our planet goes through phases of light and dark,

and day and night.

And so our behavior adjusts accordingly.

Some people have a really hard time napping,

especially when the sun is out.

We like to mimic the environment

that we sleep in at night.

So keep it dark,

or put some dark sunglasses on,

anything that helps your body feel

like it's time to take a nap.

Can you learn something new while you sleep?

The answer is much more complicated than a simple yes or no.

You're not gonna learn a language

just by playing language tapes while you're sleeping.

If you've been working on something during the day

and trying to learn something new,

auditory cues during the night

to help reinforce that knowledge, may help.

The key is we don't wanna disrupt sleep

while we're trying to do that.

More time in bed does not mean more sleep.

If you're lying in bed awake, looking around,

and especially if you're lying in bed

getting frustrated that you're not sleeping,

and worrying about how you're gonna do the next day,

or when you're gonna finally get some sleep,

or how many hours you're gonna sleep.

It's not helping the problem.

There are things we can do to optimize our sleep.

Having a comfortable mattress,

making sure that your body's not experiencing stress points,

or that your muscles and joints

are not misaligned during sleep,

can help improve the quality of your sleep.

Some people find that using a weighted blanket

helps them feel more secure during sleep,

and that weight on their body,

as well as potentially near their forehead,

helps calm them.

Though we're warm-blooded animals,

our body temperature is not the same throughout the day.

The lowest point of our body temperature

is when we're in deep sleep.

In some cases, cooling our heads

as we're trying to fall asleep

may actually help us fall asleep.

Some people have tried to do things

as simple as putting a cool compress on their head,

as they're trying to fall asleep.

A lot of people claim a hot or warm bath before sleep helps.

It actually may help cool the body,

because the blood flow is going out to the surface,

cooling our core a little bit more,

and that may help us fall asleep.

We also don't want to necessarily be productive

when we can't sleep,

because the goal is to calm our nervous systems down.

Better off getting up and doing something

that I would say is dull, boring, in a dim light.

We want to try to avoid bright light,

and especially blue light,

'cause that can get us activated again,

make it even more difficult to fall asleep.

Melatonin supplements help you sleep.

That's true.

Melatonin is actually a hormone,

made in a part of the brain called the pineal gland.

Melatonin helps our body

regulate our sleep-wake cycles naturally.

Supplements that contain melatonin may not be good for you.

The problem with supplements is they're not all the same,

and the dose of melatonin,

the timing of it,

and how much actually gets into our body, can vary a lot,

depending on the type of supplement we take.

The timing and the dose of melatonin are important,

because our bodies react to melatonin

at different times during the day.

Depending on what we're trying to achieve,

we may wanna give a low dose of melatonin

several hours before we go to sleep,

or a higher dose right before bedtime.

Melatonin supplements and melatonin treatment

may be appropriate

for people with certain types of sleep disorders.

Taking a high-quality melatonin supplement

to help fall asleep

when you're dealing with an unusual situation like jet lag,

or shift work,

may be appropriate,

but taking melatonin supplements all the time

may be covering up a problem that needs to be looked into.

Insomnia is all in your head.

That's a myth.

Insomnia's when people may have trouble falling asleep,

staying asleep, or waking up before they intend to.

Insomnia can be related

to both issues relating to our minds, and our bodies.

Sleep disorders and mood disorders

are really interconnected,

and both can affect each other.

If we're having difficulty

coping with our feelings and emotions

that can certainly impact our sleep, and vice versa.

If we're not sleeping well,

we often have a tough time regulating our emotions as well.

Trouble falling asleep

can be related to the way we deal with stress or anxiety,

or if we have trouble shutting off our brains,

as we try to get to sleep.

Trouble staying asleep may be a problem

with the way we're breathing during sleep,

or movements during sleep.

If you've done your best to improve your sleep environment,

and your sleep hygiene and habits,

and still suffer from disrupted sleep,

and waking up frequently at night,

that may be a sign of a sleep disorder,

and that may be a time

to get advice from a medical specialist.

Snoring is harmless.

That's definitely a myth.

When we sleep, our muscles relax,

including the muscles in the back of the throat.

Depending on the size and shape

of the soft tissues in the back of the throat,

the tonsils,

the uvula, which hangs from the roof of the mouth,

and the tongue,

as well as the size of our jaw,

the position that we sleep in,

medications we may be taking,

all these factors may interact

to cause some people to partially, or completely,

collapse the airway during sleep.

Partial collapse and vibration of that tissue

causes a snore sound.

So, can snoring be harmful?

If the snoring is actually more than just snoring

and interfering with our breathing,

and causing oxygen levels to drop,

then we call it sleep apnea.

Sleep apnea

is when our bodies experience repetitive collapse

of the airway during sleep,

causing disruption in sleep and drops in oxygen levels.

If this goes on for a long period of time untreated,

it can result in symptoms of insomnia,

frequent nighttime awakenings,

waking up tired or foggy-headed,

and daytime sleepiness.

Over the long term,

it can increase the chances of other health problems,

like high blood pressure,

diabetes,

and mood disorders.

In the US, about a third of people with sleep apnea

are not overweight.

Sleep apnea is more common in men than women,

but women can develop sleep apnea too,

especially after menopause.

If someone tells you you snore, or you know that you snore,

and especially if someone has commented

that they've seen you stop breathing at night,

that may be a sign of sleep apnea,

and you should probably get that checked out by a doctor.

We eat eight spiders a year while we're sleeping.

That is definitely a myth.

We eat only five spiders a night when we're asleep.

Just kidding.

When we sleep,

we may inhale or microaspirate stuff that's in our mouth.

This is usually not a big problem.

We don't swallow or chew when we're sleeping

as much as we would while we're awake.

[dramatic music]

Thanks for tuning in.

I hope this information today

will help you get a better night's sleep,

and better health.

Sweet dreams.