Falling Asleep Randomly? Blame It on These Two Things

Sleeping at random times is a sign that something is amiss. Learn what the likely causes are and get tips on how to correct this snoozing habit.
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Jeff Kahn, M.S., Rise Science Co-Founder
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Man falling asleep randomly on grass with head on laptop

For insomniacs, the ability to fall asleep as and when you like may seem like a dream come true. But what if you're falling asleep randomly at your work desk, in the lunch cafeteria, and behind the wheel? You can see how impromptu naps are an inconvenience and social embarrassment at best, and a danger to your personal safety — and others — at worst.

Clearly, involuntarily dozing off is unnatural (unless you’re snoozing during your afternoon dip, which is another story). For the most part, sleep debt and its close accomplice, circadian misalignment, are the likely culprits behind your unintentional naps.

The good news is, you can put a stop to randomly nodding off, and we're going to teach you how to do just that. Read on to find out how you can feel and function at your best — or as close to it as possible — instead of falling asleep randomly.

Falling Asleep Randomly Is Handicapping Your Daily Life

Catching 40 winks during work hours is hardly the way to win over your boss and get the promotion you've been eyeing. But looking at the big picture, falling asleep randomly does more than hurt your chances of career progression. In fact, if you're at the helm of your organization, your involuntary catnaps may possibly be dragging the firm's bottom line into the red.

Falling asleep randomly is staunch evidence sleep and productivity aren't mutually exclusive; they are two sides of the same coin. You can't sacrifice sleep for productivity because the human body just isn't designed that way.

Unintentional snoozing can also do a number on your social life. For instance, drifting off mid-convo during your first date is probably not going to pave the way for a second one. On a more serious note, the uncontrollable zzz's can jeopardize your personal safety and others as well. Picture this: Would you want to sit in a fast-moving car with the driver nodding off at the wheel?

This Is Why You’re Falling Asleep Randomly 

Assuming you don't have a medical condition, the Two Laws of Sleep explain the most common reasons you're falling asleep randomly are:

Let's look at how each factor is inciting your involuntary snores at inappropriate times.

Sleep Debt: What It’s All About

Falling asleep randomly: entrepreneur asleep on her desk

The average person often perceives sleep debt as prior sleep loss, and they aren't wrong. At Rise, we classify it into:

  • Acute sleep debt: This is the amount of sleep your body has skipped out on in the past 14 days, relative to your sleep need (the genetically determined amount of sleep your body needs).
  • Chronic sleep deprivation: When sleep debt has a chance to pile up over several months and years, it quickly snowballs into chronic sleep deprivation. If you're chronically sleep-deprived, you most certainly have acute sleep debt, too.

In many cases, sleep debt is the primary reason why you're falling asleep randomly. Scientists have confirmed the brain optimally functions for a maximum of 16 hours of wakefulness. Anything beyond that, and you're most likely running on low fuel, potentially sabotaging every aspect of your daily life.

In fact, going without sleep for 18 hours (just two hours past your maximum limit of wakefulness) means you're as cognitively impaired as someone with a blood alcohol concentration (BAC) of 0.05%, even if you meet your sleep need afterward. When you skip out on one hour of your sleep need for 10 nights in a row, your brain is now as impaired as if you had forgone sleep for 24 hours straight, akin to a BAC of 0.10% (which is higher than every state’s legal limit).

Do You Know How Much Sleep You Need — And Are Getting?

For many people, sleep insufficiency often stems from not knowing our biological sleep need. Publicized generalizations of 7-9 hours of sleep per night have fooled us into believing everyone's sleep need is exactly the same when that's far from the case.

The truth is, your genes determine your sleep need the same way your eye color and height are inborn. For context, the average person needs 8 hours and 10 minutes per night (plus or minus 44 minutes or so), with a minority (13.5%) requiring a longer sleep schedule of nine hours or more.

To complicate matters, we often overestimate our sleep duration. Going to bed at 10 p.m. and waking up at 7 a.m. won’t translate to nine hours of uninterrupted, invigorating sleep. Excessive sleep latency (taking too long to fall asleep) and sleep fragmentation (waking up in the middle of the night) mean you're asleep for fewer than nine hours. If your biological sleep need is indeed that amount, you can predict how your sleep debt mounts in just a few nights.

The Day-to-Day Perils of Sleep Insufficiency 

Ample research shows a clear link between sleep deprivation and microsleeps — you involuntarily fall into unconsciousness for a few to several seconds. Flashback to all those instances when you briefly closed your eyes out of sheer tiredness at work, only to have your colleague subtly nudge you back into wakefulness.

But the scary thing is, you don't actually have to close your eyes to microsleep. What you misconstrue as spacing out after not meeting your sleep need is most likely a classic example of said phenomenon. While it may seem like you're awake, research shows brainwave activity in some areas switches off such that you aren't fully functioning, much less in top form.

This is why William Dement, one of the pioneers of the field of sleep medicine, often said, "Drowsiness is red alert." Minute amounts of sleep debt are enough to suffuse your system with daytime drowsiness. You’re now at a greater risk of falling asleep randomly at work, in school, and everywhere else, not to mention suffering all of the adverse effects of sleep debt to your physiology, cognition, and mental health behind the scenes.

What's worse is our brain subjectively adapts to prior sleep loss. We think we're doing fine when we're anything but. Your circadian rhythm's peaks and dips also mask the true extent of sleep deprivation. If you’ve ever pulled an all-nighter only to feel a “second wind” in the mid-morning (which is actually your first circadian peak), you know how this feels. Consequently, you’re lulled into a false sense of reality that you're coping well with less sleep than you need.

Case in point: when you start making mistakes on your Excel spreadsheet or when you mix up your kids' packed lunches. This is where an app like RISE can help you put things into accurate perspective, but more on that later.

On a physiological level, chronic sleep insufficiency lays the groundwork for future health problems: Think a toxic blend of metabolic syndrome, heart disease, Type 2 diabetes, stroke, certain cancers, and even psychiatric disorders like depression.

Sleep deprivation also means you're 60% more likely to experience strong emotions while blunting your empathy compass. You can easily predict how that spells trouble for both your personal and professional lives.

Circadian Rhythm: The Internal Clock That Times It All

RISE app screenshot showing your peak energy and dip times
The RISE app shows your daily energy peaks and dips on your Energy Schedule.

Your circadian rhythm is your internal body clock that governs every biological process, from hormone production and temperature regulation to when you sleep and wake. The times you're naturally inclined to carry out these activities come under the realm of your chronotype. As one study puts it, your chronotype is the “expression of individual circadian rhythmicity.”

Teaming up with your circadian rhythm and chronotype thus gives you the best chance of getting the most out of your day. That's why the RISE app visualizes your natural sleep-wake inclinations and daily energy fluctuations as peaks and dips on your Energy Schedule. It helps you relegate less demanding activities to your circadian dip (so you still feel productive) and reserve your peaks for more challenging tasks.

It’s Natural to Fall Asleep at Certain Times of Day

During certain times of the day, you're naturally more apt to feel drowsy. This includes your afternoon dip and nighttime sleep (the RISE app breaks down the latter into your evening wind-down, Melatonin Window, biological night, and Grogginess Zone). One example that hits close to home would be how you find yourself sinking into a stupor after lunch.

In these instances, you may mistake your energy dips as periods of unplanned napping. But in reality, that's just your body's way of telling you to slow down, rest, and refuel. Keep in mind these energy dips occur day in and day out, no matter if you've met your sleep need (although sleep debt will undoubtedly deepen the low-energy troughs).

The Chagrin of Circadian Misalignment

In a perfect world, your body clock would be running smoothly. This helps you do the right things at the right times to bring your 'A' game into every aspect of daily life.

Unfortunately, various factors trip up your body clock, resulting in circadian misalignment. Consequently, you snooze at the worst possible times. Even if you've consistently met your sleep need and hold minimal sleep debt (below five hours), going against the flow of your circadian rhythm can still make you sluggish at times.

Social jetlag is the most relatable example of circadian misalignment. Many of us keep an early sleep schedule on work days but stay up late on our days off. This leads to a mismatch between our social and biological clocks.

Naturally, we find it hard to transition back to 6 a.m. wake-up calls on Monday morning. Plus, sleep procrastination on a Sunday night — cue the phone-texting, Instagram-scrolling, and Netflix-bingeing — doesn't help matters either.

Similarly, those on shift-work duty (think paramedics, firefighters, and police officers) also struggle with the all-too-common shift-work disorder. Self-professed night owls living on an early-bird schedule are no stranger to the ill effects of circadian misalignment, too.

So, if you find yourself falling asleep randomly due to an out-of-whack body clock, know that you're not alone.

The Good News: You Can Stop Falling Asleep Randomly

So far, you've had a bird's eye view of the reasons why you're falling asleep randomly. Now, it's time to use the Two Laws of Sleep to curb this inconvenient — and injurious — habit for good. At Rise, our mantra is: Perfect healthy sleep habits that align with your circadian rhythm to cut down on sleep debt.

Cut Down Sleep Debt

RISE app screenshot showing how much sleep debt you have
The RISE app shows your running sleep debt.

We've previously established how hard it is to track down sleep debt simply because not many people know their actual sleep need. Nor are they aware of the exact amount of nighttime sleep they had.

If you belong to the majority, fret not — all you need is the RISE app.

Leveraging sleep-science-based models and pulling the past 365 nights of sleep data tracked by your phone, RISE is in the perfect position to learn your unique sleep biology and calculate your sleep need in hours and minutes. Just tap the profile icon on the top-right corner of the Sleep screen to find your individual sleep need.

RISE app screenshot showing your sleep need
View your profile to see your unique sleep need.

You never have to agonize over how much rapid eye movement (REM) sleep you got or how much time you've spent in the four stages of sleep. Nor do you have to bother with good- and bad-quality sleep, which — by the way — there's no scientific consensus on what the term means.

On top of that, RISE uses phone motion-based sleep detection to measure how much sleep you’ve had based on your sleep and wake times passively in the background, without needing input from you. Stacking this data up against your sleep need gives you the precise amount of sleep debt your body is carrying, which you can view on the Sleep screen.

Once you're cognizant of your sleep need and sleep debt, this is a good place to start paying the latter down and curb falling asleep randomly. Here’s how:

  • Bring your bedtime forward: For the next few nights, an early bedtime is the fastest — and simplest — way to bring down your sleep debt. Just make sure your new bedtime is within your Melatonin Window (which you can check in the RISE app) to doze off more easily.
  • Nap during your dip: To avoid falling asleep randomly, say during your kid's school play, slot in a nap during your afternoon dip (check it out on the Energy Schedule in the app). Follow our guide on the do's and don'ts of daytime napping.
  • Sleep in as a last resort: You may consider a later wake time if the previous two options don't fit your schedule. Bear in mind, though, a lie-in can thwart your internal clock, so limit it to no more than an hour of your usual rise time.

Making minor tweaks to your sleep schedule can help keep your sleep debt in check, so you aren't falling asleep randomly. Of course, to optimize your sleep patterns, you'll have to align them with your chronotype. If you're a night owl who has to abide by an early sleep-wake schedule, check out our guide on how to become a morning person.

Get On the Right Side of Your Circadian Rhythm

Instead of working against your internal clock, prioritize working with it to help you feel and function at your best.

To accomplish that, think in terms of energy management rather than time management. Structure your day according to the energy peaks and dips of your circadian rhythm, keeping good sleep hygiene top of mind. This will help you achieve better sleep at night, so you don't knock out at the most inopportune times.

Here's how: Take note of your two energy dips — the afternoon dip and the period from wind-down to wake-up. This way, you're less likely to fall prey to the notion that you're falling asleep randomly. Use the RISE app to plan ahead for your energy dips with dip-friendly activities during these periods:

  • Grogginess Zone: Wake-up grogginess is part and parcel of your sleep-wake cycle. Make it a point to bask in the morning sun to help you awaken more quickly. A cup of joe, a known stimulant for boosting alertness, also helps minimize morning sleep inertia.
  • Afternoon dip: Napping during this low-energy period is the perfect chance to rest and recharge without feeling guilty or like you're falling asleep "randomly." It's also a great way to catch up on sleep debt, as mentioned earlier.
  • Evening wind-down: As the day draws to a close, your body naturally slows down in preparation for sleep. To help you fall asleep easily and sleep through the night, a relaxing evening wind-down is non-negotiable. Just try not to doze off during this period!

The RISE app also helps you master simple yet effective sleep-promoting lifestyle changes from sunrise to sunset, based on your unique chronobiology. For instance, it tells you when to cut off your caffeine consumption with the "Limit Caffeine" habit on your Energy Schedule. This way, you'll never have to worry about your second cup of coffee delaying your bedtime that night.

Explore our comprehensive Sleep Guide for more tips.

One More Reason You May Be Falling Asleep Randomly

Woman asleep while driving

If you aren't struggling with sleep debt or circadian misalignment, but are still caught off guard by the zzz's, it may be an underlying medical condition.

Various sleep disorders, such as obstructive sleep apnea (obstruction to your airways during sleep) and restless legs syndrome, hamstring your odds of a good night's sleep. Medical conditions like thyroid disorders and specific medications such as antihistamines and antidepressants also incite excessive daytime sleepiness.

But when it comes to falling asleep in a sudden, uncontrolled manner, narcolepsy is more often than not to blame.

For the uninitiated, narcolepsy is a rare brain disorder that's categorized into:

  • Narcolepsy type 1, also known as narcolepsy with cataplexy (loss of muscle tone or temporary muscle weakness)
  • Narcolepsy type 2, also known as narcolepsy without cataplexy

Narcolepsy impairs REM sleep due to low levels of hypocretin, a brain chemical that roots you in wakefulness. Usually, people with narcolepsy experience:

  • Excessive daytime sleepiness
  • Sleep attacks, in which you're falling asleep randomly
  • Sleep paralysis, in which you feel like you're awake but can't move for a short while
  • Hypnagogic and hypnopompic hallucinations, which occur when you're falling asleep and waking up, respectively
  • Sleep fragmentation, which refers to waking up in the middle of your sleep cycle

Statistics indicate narcolepsy type 1 affects "14 per 100,000 people," while narcolepsy type 2 is present in "65.4 per 100,000 people." Sleep specialists often recommend a combination of treatment options like behavioral modifications (for example, planned daytime naps) and drowsiness-banishing medications (like modafinil).

Even though pharmacologic interventions are necessary for tackling the symptoms of narcolepsy, you still need to have a solid foundation in good sleep hygiene so you’re less likely to accidentally doze off.

Stop Living Suboptimally; Start Living Your Best Life

Falling asleep randomly can do a number on your quality of life, but you don't have to put up with it. In the case of sleep debt and circadian misalignment, unintentional snoozing is completely preventable. All you have to do is let the RISE app guide you on your quest toward consistently meeting your sleep need and playing by the tune of your circadian rhythm.

If a health issue like narcolepsy is at play, consult your primary doctor on the steps to take. Just remember that pills and other medical interventions are only one part of your treatment plan. You'll have to pair them with proper sleep hygiene for better energy during daylight.

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About Rise
Rise is the only app that unlocks the real-world benefits of better sleep.

Instead of just promising a better night, we use 100 years of sleep science to help you pay down sleep debt and take advantage of your circadian rhythm to be your best.

Over the past decade, we've helped professional athletes, startups, and Fortune 500s improve their sleep to measurably win more in the real-world scenarios that matter most.

Rise Science is backed by True Ventures, Freestyle Capital, and High Alpha; investors behind category winners Fitbit, Peloton, and Salesforce Marketing Cloud.
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Try 7 days free

The power behind your next best day

RISE makes it easy to improve your sleep and daily energy to reach your potential

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