# How do I get through the day after a bad night?

> How are you this morning? If your eyes feel gritty and the whole day is ahead, the first hour is often the hardest, and one short night usually takes less from you than this moment suggests. If someone else kept you up, and may again tonight, [what helps is different for you](#if-someone-else-kept-you-up).

**In short:** Your body guards its deep sleep[^1] in a short night and makes up by sleeping more deeply[^2] the next, so today's tiredness is working for tonight. Today may bring a few foggy moments[^3] and a flatter mood, likely milder than in studies of whole nights without sleep. You can get through to bedtime with bright light, your coffee early, a nap if you need one and no driving while you're drowsy.

The alarm is often the worst of it: the moment you have to stand up and meet a day that didn't wait for you to be ready. There may be work ahead, or children to get out of the door, a meeting or a drive, and from here the hours until bedtime can look very long. And there's often a smaller worry about tonight, too: whether it will go the same way. If you only have a minute, you could drink your first coffee where the daylight can reach you, on the back step or at the brightest window in the house.

**If you’d like to try something this morning**

If you can, you could step outside for a few minutes as well, as far as the end of the path and back. Later, after lunch, you could look for a bright spot again.

## Will today be as bad as it feels right now?

The groggy, woolly stretch just after the alarm has a name, sleep inertia, and it's stronger after a short night[^4]. In one brain-imaging study, it cleared from the front of the brain in between five and thirty minutes[^4]. So the way you feel as you first stand up is a poor guide to the hours that follow.

As the morning goes on, what you're most likely to notice are small things: brief lapses where you miss something for a moment[^3]. Your reasoning tends to suffer less. Researchers pooled studies that kept people awake for up to two days, far longer than one short night. Even then, any change to reasoning was small enough to be uncertain[^3]. One short night likely takes less still.

You may feel flatter too. What sleep loss takes most is cheerfulness, energy and interest[^5]. If you're short with people today, or everything looks a little gray, you can put much of that down to the night.

Through the day, sleepiness tends to rise and fall. Many people have a dip in alertness in the mid-afternoon[^6]. It comes from the body clock, and it arrives whether you've had lunch or not, though a heavy, starchy lunch can deepen it. On an ordinary day the urge to sleep then eases to a low point shortly before your usual bedtime[^2], so after hours of yawning you may find yourself oddly bright in the evening. You might catch yourself wiping down the kitchen or picking up a book you'd given up on by lunchtime. All through that second wind, the pressure for deep sleep goes on building steadily[^2].

**How sleepy you feel rises and falls, while the pressure for sleep only builds**

Drawn for an ordinary day from a 7am alarm to an 11pm bedtime. Follow the dotted line through its rises and falls, from the groggy first minutes[^4] to the afternoon dip[^6] and the evening's brighter spell[^2], while the solid line keeps climbing[^2]: feeling more awake in the evening doesn't mean the pressure has gone. The pattern comes from studies of healthy adults on regular schedules, rather than the day after a short night.

07:00

23:00

How sleepy you feel

Pressure for deep sleep

- **The alarm**

- **Mid-morning**

- **Afternoon dip**

- **Second wind**

- **Bedtime**

## Will I make back the sleep I lost?

You may be counting the hours you lost and wondering whether they'll ever come back. Your body does make up for them, in its own way, and the way it does so works in your favor. Your body sets the depth of your deep sleep mainly by how long you've been awake[^2], so every hour you're up today adds to the sleep pressure that will take you into deep sleep tonight. The tiredness you feel now is that pressure building. After sleep loss, the next night begins with deeper sleep than usual[^2], and returns to its ordinary pattern later on.

A short night keeps more deep sleep than it feels as if it did. When healthy adults in a sleep lab were given only four hours in bed, they still got about sixty minutes of deep sleep[^1], against sixty-nine on a ten-hour night. Most of what their short night cut away was lighter sleep, and their minutes of deep sleep were kept almost whole.

When the same people had a run of five four-hour nights and then a long night to recover, they made it up through both deeper sleep and extra length[^1], and nobody knows how much came from each. There isn't a good figure yet for how many of one night's lost hours come back. Counting the hours misses that a big part of the payback is depth.

**How did researchers measure deep sleep in a short night?**

The four-hour figures come from a lab study of 159 healthy adults[^1] aged 22 to 45, who first slept ten hours in bed for a few nights so their sleep was fully topped up, then spent five nights with four hours in bed while their brain waves were recorded. On the ten-hour nights they had about sixty-nine minutes of slow-wave sleep. On the first four-hour night they still had about sixty, and by the fifth, as pressure built, about sixty-five.

The researchers also measured how intense that deep sleep was, which is a finer gauge. By that measure it fell further, to about two thirds of its usual level on the first short night. So a short night does take something from deep sleep. It still keeps far more of it than of the lighter stages.

The picture of the next night starting deeper comes from classic lab work[^2]. In one study, researchers kept nine people awake for thirty-six hours, much longer than a short night. Their recovery sleep began with unusually deep slow-wave sleep and fewer brief wakings. Later in the night it went back to its usual pattern.

## Is it worth sleeping in, napping or going to bed early to catch up?

If you had the time to sleep last night and it wouldn't come, you may be tempted to win the hours back this morning or tonight. If someone else's needs kept you up, [what helps when the nights belong to someone else](#if-someone-else-kept-you-up) is different. In one British study that followed ordinary sleepers for a year, about a third had a bout of short-term insomnia[^7], and it often passed. What can turn it into a longer pattern[^8][^7] is the way we respond: extra time in bed, frequent naps and worry about the next night. The first two you can decide about this morning. The worry is harder, because you can't simply choose not to have it. What helps is knowing what you'd do with the hours if it keeps you up, and [Should I get up if I can’t sleep?](https://nitez.com/getting-up-at-night) goes into that.

**I lay awake, so I need to catch up on the sleep I lost.**

It's how most debts work, and after hours of lying awake, bed is where every part of you wants to be. Sleeping in, or turning in at eight, feels like looking after yourself.

Wanting to be in bed makes sense, and the body does make up, partly by sleeping longer and partly by sleeping more deeply. That depth comes from time spent awake, so extra hours in bed this morning or this evening tend to use up the pressure that would have deepened tonight. The treatments for long-running insomnia use the same pressure, limiting time in bed to build up sleep drive[^9], though that's a guided therapy for weeks of bad nights and not something to start after one. The advice about this one morning comes from how sleep pressure works, rather than from a trial. Each waking hour you keep today adds to tonight's pressure.

A nap draws on that same store of pressure, especially late in the day. In one small study, an early-evening nap made people much slower to fall asleep that night[^2]. If you need one, a short nap earlier in the afternoon takes less from tonight. In one study, young adults whose night had been cut to about five hours napped for ten minutes at 3pm and felt and performed better straight away[^10]. A half-hour nap left them groggier at first. Ten minutes is well within the usual guide of around twenty minutes or less. The guide is loose, because how groggy a short nap leaves you depends on how short your night was and the time of day[^11][^4]. [Are naps good for you?](https://nitez.com/are-naps-good-for-you) goes further into it.

If the bad nights have been running on for weeks, that's a different thing from one night, with its own help in [What is CBT for insomnia, and what would it ask of me?](https://nitez.com/cbt-for-insomnia) So after a night of lying awake, the plan with the best grounds is also the plainest: up at your usual time, any nap short and early, and bed at your ordinary hour. Each part of it saves the day's pressure for tonight instead of spending it now.

## What helps the day go a little easier?

By mid-morning you may find yourself reaching for another coffee, and the morning is when it takes least from tonight. Caffeine taken even six hours before bed can cut into that night's sleep[^12]. In one study, healthy sleepers at home took the caffeine in about four cups of brewed coffee six hours before bedtime. It cost them more than an hour of sleep. So you could have your cups early and let the afternoon go without, and [How long does caffeine stay in your system?](https://nitez.com/caffeine-and-sleep) has the detail.

Light may help with the afternoon, too. In a small lab study, people who had slept five hours a night for two nights were less sleepy and quicker to react[^13] when they sat in bright indoor light from noon to 5pm than when they sat in dim light. That's one small study, but a seat by a window after lunch, or a few minutes outside, asks little of you.

As attention is what slips most, it may help to go easy on work that needs it unbroken, like checking figures or measuring out a medicine dose. A dose is worth checking twice, however clear you feel. If a big decision is waiting, you could put it off where you can, or talk it through with someone.

## Is it safe to drive today?

Driving is where the brief lapses and the afternoon dip meet. Among drivers in real US crashes, those who'd slept about five hours in the day before had nearly twice the odds of causing their crash[^14] as those who'd slept seven to nine. In a driving simulator, researchers sat sleepy volunteers through a long, dull afternoon drive. Their sleepy incidents peaked in the mid-afternoon[^15]. A coffee beforehand cut those incidents to about a third[^15] of what they were without caffeine. That's better, but a third is still a lot. In a second study, drivers who'd slept five hours tried cold air from the window and the radio turned up, and neither made any real difference[^16] to how they drifted. For your drive today, coffee lowers the danger without removing it, and the window and the radio do next to nothing.

If you feel drowsy, please don't drive. If you can, let someone else take the wheel, or wait a while before you set off. Some days there's no one else and the drive has to happen, and then it may help to keep away from the mid-afternoon if you have the choice. If drowsiness comes over you on the road, please pull over somewhere safe, have a coffee and a short nap there, and then drive on only as far as you need to. In the same simulator, coffee followed by a short nap cut incidents to under a tenth[^15], so on a drive you can't avoid, it's a way of lowering the risk.

## If someone else kept you up, and tonight may be the same

If you were up with a baby, a sick child or someone you care for, there was no choosing, and much of what's said about protecting your sleep doesn't fit a night that belongs to someone else. The advice against sleeping in, napping and early nights to catch up is meant for someone who had the time to sleep and couldn't, and it isn't for you. Sleep is worth taking whenever it's offered, whether that's a short nap while the baby sleeps or an early night to get a stretch in before the first waking.

If you've had a baby, you know the nights are shorter. Among German parents, mothers in the first three months after a birth slept about an hour less a night than before pregnancy[^17], and fathers about thirteen minutes less. How broken the nights are may matter as well. When researchers gave first-time mothers wrist monitors and a reaction test each morning, the mothers often got a near-normal total, but in pieces[^18]. Week by week, their lapses of attention in the morning rose[^18], even as more of their time in bed went on sleep. It's one early study, of new mothers only, but it suggests that broken nights wear on your attention even when the hours add up. So anything that adds unbroken stretches, whenever they come, may help most.

If there's someone to share the nights with, you could take turns, so that each of you has one longer stretch of unbroken sleep. That may give the body room to sleep more deeply, an idea that comes from how sleep pressure works and hasn't been well studied. Among the same mothers, those whose sleep fell in a steadier, earlier window had fewer lapses[^18], so steadier, earlier hours may be worth trying on the nights that allow it.

On a run of short nights, feeling all right is a weaker guide than usual, mostly when it comes to driving. When people in a lab were kept to six hours or less a night, their attention kept slipping[^19] while how sleepy they felt rose only a little[^19]. They were allowed no naps, so their picture is a ceiling, and the naps you can sometimes snatch may make yours milder. On a morning when you need to drive, it may be safer to go by how the nights have been than by how you feel.

If you care for an adult, the research on carers' sleep is thin, though support aimed at it seemed to help a little[^20], by carers' own account. For you too, any sleep the days and nights leave room for is worth having, and an unbroken stretch may do more for you than the same hours in pieces. If anyone can take a night, or even part of one, that stretch may be the thing to ask them for.

**Who was studied in the research on parents and carers?**

The figure for new parents comes from a large German panel[^17] of more than four thousand mothers and fathers who reported their sleep each year, before and after a birth.

The broken-sleep findings come from seventy-one first-time mothers in West Virginia[^18], who wore a wrist monitor for twelve weeks and took a five-minute reaction test each morning. It was an observational study, so the steadier window may reflect other differences between the women.

The lab figures come from healthy adults aged 21 to 38[^19] kept to four, six or eight hours in bed for two weeks. The review of support for carers pooled randomized trials of unpaid carers[^20], where the support varied a good deal and the evidence was rated low in quality.

## What about tonight?

All day, the pressure for deep sleep has been building[^2]. After sleep loss, the sleep that follows tends to begin more deeply than usual[^2]. If your night will be broken again by someone who needs you, any unbroken stretch it allows, even an early hour before the first waking, may do you the most good. If the night is yours, an ordinary bedtime and the lights low are all it asks. And if sleep is slow to arrive, nothing has been lost while you wait. Your body sets that pressure by how long you've been awake[^2], and it goes on building through the waiting.

Most of these studies were of healthy young adults in sleep labs, and much less is known about how older adults, people with long-running insomnia or people caring for an adult recover.

- **After sleep loss, the next sleep begins with deeper slow-wave sleep than usual.** well-established

- **In studies of up to two days without sleep, the clearest effect is brief lapses of attention, while the change to reasoning is small, so one short night is likely milder.** well-established

- **Sleep loss lowers mood, especially cheerfulness and energy, across studies of whole nights without sleep and of shorter nights.** well-established

- **Deep sleep is largely kept even when a night is cut to four hours.** good-evidence

- **An evening nap makes it slower to fall asleep that night.** good-evidence

- **After a five-hour night, a ten-minute afternoon nap helped at once, while a thirty-minute nap left people groggy first.** good-evidence

- **In one small trial in healthy sleepers, 400 milligrams of caffeine, about four cups of coffee, taken six hours before bed cut that night's sleep by more than an hour.** early-evidence

- **Sleeping five hours or less sharply raises the odds of causing a crash.** good-evidence

- **In one small lab study, bright indoor light in the afternoon eased sleepiness after two short nights.** early-evidence

- **Taking turns through the nights, so each person gets a longer unbroken stretch, may help with broken sleep.** not-well-studied

## Related questions

- [Are naps good for you?](https://nitez.com/are-naps-good-for-you)
- [How long does caffeine stay in your system?](https://nitez.com/caffeine-and-sleep)
- [What is deep sleep, and am I getting enough?](https://nitez.com/deep-sleep)
- [Should I get up if I can’t sleep?](https://nitez.com/getting-up-at-night)
- [What is CBT for insomnia, and what would it ask of me?](https://nitez.com/cbt-for-insomnia)

## Sources

[^1]: Banks S, Van Dongen HP, Maislin G, Dinges DF. Neurobehavioral dynamics following chronic sleep restriction: dose-response effects of one night for recovery. Sleep. 2010;33(8):1013–1026. [PubMed](https://pubmed.ncbi.nlm.nih.gov/20815182/) · [DOI](https://doi.org/10.1093/sleep/33.8.1013) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC2910531/)
[^2]: Dijk DJ. Regulation and functional correlates of slow wave sleep. Journal of Clinical Sleep Medicine. 2009;5(2 Suppl):S6–S15. [PubMed](https://pubmed.ncbi.nlm.nih.gov/19998869/) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC2824213/)
[^3]: Lim J, Dinges DF. A meta-analysis of the impact of short-term sleep deprivation on cognitive variables. Psychological Bulletin. 2010;136(3):375–89. [PubMed](https://pubmed.ncbi.nlm.nih.gov/20438143/) · [DOI](https://doi.org/10.1037/a0018883) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC3290659/)
[^4]: Trotti LM. Waking up is the hardest thing I do all day: Sleep inertia and sleep drunkenness. Sleep medicine reviews. 2017;35:76–84. [PubMed](https://pubmed.ncbi.nlm.nih.gov/27692973/) · [DOI](https://doi.org/10.1016/j.smrv.2016.08.005) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC5337178/)
[^5]: Tomaso CC, Johnson AB, Nelson TD. The effect of sleep deprivation and restriction on mood, emotion, and emotion regulation: three meta-analyses in one. Sleep. 2021;44(6):zsaa289. [PubMed](https://pubmed.ncbi.nlm.nih.gov/33367799/) · [DOI](https://doi.org/10.1093/sleep/zsaa289) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC8193556/)
[^6]: Monk TH. The post-lunch dip in performance. Clinics in Sports Medicine. 2005;24(2):e15–e23. [PubMed](https://pubmed.ncbi.nlm.nih.gov/15892914/) · [DOI](https://doi.org/10.1016/j.csm.2004.12.002)
[^7]: Ellis JG, Perlis ML, Neale LF, Espie CA, Bastien CH. The natural history of insomnia: focus on prevalence and incidence of acute insomnia. Journal of Psychiatric Research. 2012;46(10):1278–1285. [PubMed](https://pubmed.ncbi.nlm.nih.gov/22800714/) · [DOI](https://doi.org/10.1016/j.jpsychires.2012.07.001)
[^8]: Patel D, Steinberg J, Patel P. Insomnia in the Elderly: A Review. Journal of Clinical Sleep Medicine. 2018;14(6):1017–1024. [PubMed](https://pubmed.ncbi.nlm.nih.gov/29852897/) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC5991956/) · [DOI](https://doi.org/10.5664/jcsm.7172)
[^9]: Edinger JD, Arnedt JT, Bertisch SM, Carney CE, Harrington JJ, Lichstein KL, et al. Behavioral and psychological treatments for chronic insomnia disorder in adults: an American Academy of Sleep Medicine clinical practice guideline. Journal of Clinical Sleep Medicine. 2021;17(2):255–262. [PubMed](https://pubmed.ncbi.nlm.nih.gov/33164742/) · [DOI](https://doi.org/10.5664/jcsm.8986) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC7853203/)
[^10]: Brooks A, Lack L. A brief afternoon nap following nocturnal sleep restriction: which nap duration is most recuperative? Sleep. 2006;29(6):831–840. [PubMed](https://pubmed.ncbi.nlm.nih.gov/16796222/) · [DOI](https://doi.org/10.1093/sleep/29.6.831)
[^11]: Hilditch CJ, Dorrian J, Banks S. A review of short naps and sleep inertia: do naps of 30 min or less really avoid sleep inertia and slow-wave sleep? Sleep Medicine. 2017;32:176–190. [PubMed](https://pubmed.ncbi.nlm.nih.gov/28366332/) · [DOI](https://doi.org/10.1016/j.sleep.2016.12.016)
[^12]: Drake C, Roehrs T, Shambroom J, Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. Journal of Clinical Sleep Medicine. 2013;9(11):1195–1200. [PubMed](https://pubmed.ncbi.nlm.nih.gov/24235903/) · [DOI](https://doi.org/10.5664/jcsm.3170) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC3805807/)
[^13]: Phipps-Nelson J, Redman JR, Dijk DJ, Rajaratnam SM. Daytime exposure to bright light, as compared to dim light, decreases sleepiness and improves psychomotor vigilance performance. Sleep. 2003;26(6):695–700. [PubMed](https://pubmed.ncbi.nlm.nih.gov/14572122/) · [DOI](https://doi.org/10.1093/sleep/26.6.695)
[^14]: Tefft BC. Acute sleep deprivation and culpable motor vehicle crash involvement. Sleep. 2018;41(10):zsy144. [PubMed](https://pubmed.ncbi.nlm.nih.gov/30239905/) · [DOI](https://doi.org/10.1093/sleep/zsy144)
[^15]: Reyner LA, Horne JA. Suppression of sleepiness in drivers: combination of caffeine with a short nap. Psychophysiology. 1997;34(6):721–725. [PubMed](https://pubmed.ncbi.nlm.nih.gov/9401427/) · [DOI](https://doi.org/10.1111/j.1469-8986.1997.tb02148.x)
[^16]: Reyner LA, Horne JA. Evaluation of “in-car” countermeasures to sleepiness: cold air and radio. Sleep. 1998;21(1):46–50. [PubMed](https://pubmed.ncbi.nlm.nih.gov/9485532/)
[^17]: Richter D, Krämer MD, Tang NKY, Montgomery-Downs HE, Lemola S. Long-term effects of pregnancy and childbirth on sleep satisfaction and duration of first-time and experienced mothers and fathers. Sleep. 2019;42(4):zsz015. [PubMed](https://pubmed.ncbi.nlm.nih.gov/30649536/) · [DOI](https://doi.org/10.1093/sleep/zsz015)
[^18]: McBean AL, Montgomery-Downs HE. Timing and variability of postpartum sleep in relation to daytime performance. Physiology & behavior. 2013;122:134–9. [PubMed](https://pubmed.ncbi.nlm.nih.gov/24041725/) · [DOI](https://doi.org/10.1016/j.physbeh.2013.09.003) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC3840106/)
[^19]: Van Dongen HP, Maislin G, Mullington JM, Dinges DF. The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation. Sleep. 2003;26(2):117–26. [PubMed](https://pubmed.ncbi.nlm.nih.gov/12683469/) · [DOI](https://doi.org/10.1093/sleep/26.2.117)
[^20]: Cooper CJ, Owen PJ, Sprajcer M, Crowther ME, Craige EA, Ferguson SA, et al. Interventions to improve sleep in caregivers: A systematic review and meta-analysis. Sleep medicine reviews. 2022;64:101658. [PubMed](https://pubmed.ncbi.nlm.nih.gov/35777346/) · [DOI](https://doi.org/10.1016/j.smrv.2022.101658)

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https://nitez.com/after-a-bad-night · Trouble sleeping · updated 2026-07-30