Why you feel sleepy at work, and what to do about it

Most of the time, feeling sleepy at work comes down to not getting enough sleep, made worse by things in the day itself: the body clock's natural lull in the early afternoon, a heavy lunch, too little water, hours sitting still and a dim, warm room. In the moment, a short walk, some daylight and a glass of water help most. Over a week, the real fix is more sleep, at steadier times.

If you sleep well and still fight to stay awake every day, that is different, and it is worth a doctor's look. The signs are at the end.

The usual causes

There is rarely one reason. Most sleepy days are a few of these stacked on top of each other.

• Short sleep. The biggest one by far. A night or two of six hours instead of eight adds up, and the debt shows in the afternoon. Most adults need at least seven hours a night, according to the American Academy of Sleep Medicine.
• The early afternoon dip. Many people have a natural fall in alertness somewhere after lunch, set by the body clock. Studies suggest it shows up even in people who skip lunch, and it is much deeper after a short night. Why you get sleepy after lunch covers the dip on its own.
• A heavy lunch. A big plate, especially one built around bread, pasta or something sweet, is often followed by a slow, heavy hour.
• Too little water. Being a little short of water is linked in small studies to feeling more tired and finding it harder to concentrate. The effect is modest, but it is easy to rule out.
• Sitting still. Hours in one chair, looking at one screen, make most people feel flat. Moving around tends to make them feel more awake, at least for a while.
• A dim, warm room. Low light and warm, still air tell your body it is time to rest. Many offices and home desks are both.
• Dull work. A long, repetitive task gives your brain nothing to push against. Sleepiness that was already there comes forward.

Here is the same list as a quick guide:

Why am I so tired at work after a full night's sleep?

If you are sure you sleep enough and still feel drowsy, a few common things are worth checking before anything else.

• Time in bed is not time asleep. Eight hours in bed can be well under eight hours of sleep if you take a long time to drop off, wake in the night or lie scrolling on your phone first.
• Your schedule moves around. Late weekends and early Mondays shift your body clock back and forth, so you are often awake at an hour your body thinks is night.
• Late caffeine. Coffee in the late afternoon can make sleep lighter even if you fall asleep fine. Many people don't connect the two.
• Alcohol in the evening. It can help you fall asleep but tends to make the second half of the night more broken.
• A noisy, bright or warm bedroom. Small disturbances you don't remember can still break up your sleep.
• Stress. A busy mind can keep sleep shallow, and worry makes a tired afternoon feel worse.

If none of those fits, keep reading to the doctor section. Plenty of medical conditions, and some medicines, cause daytime sleepiness, and sorting those out is a doctor's job, not a blog's.

What to do when you feel sleepy at your desk

When your eyes start closing over a spreadsheet, try these, roughly in this order.

1. Stand up and walk for five to ten minutes. Outside if you can, around the building or up and down the stairs if you can't. This is usually the fastest fix.
2. Find daylight. Step outside or stand at a window for a few minutes. Daylight, even on a gray day, is far brighter than indoor lighting, and many people find it wakes them up.
3. Drink a glass of cold water. Then refill the glass so the next one is waiting on the desk.
4. Cool the room. Open a window, take off a layer, turn the heating down a little.
5. Switch to work that moves. Take a call standing up, tidy your inbox, talk a problem through with someone. Save the dense reading for later.
6. Nap, if you can. Twenty minutes or less, and before mid-afternoon, so you don't wake up groggy or push back tonight's sleep. Naps for desk workers covers how long and where.

A coffee is fine too, if it is early enough. A cup at two may still be in your system at bedtime, so for many people the afternoon cup is where tonight's sleep, and tomorrow's slump, starts. Sugary snacks often give a quick lift and a slower drop, so a piece of fruit or a handful of nuts tends to sit better.

How to stop feeling sleepy at work over a week

The in-the-moment fixes buy you an hour. These change the pattern.

Protect your sleep first

Pick a wake time you can keep every day, weekends included, and set a bedtime that gives you at least seven hours from it. If that means going to bed much earlier than you do now, move it in steps of 15 minutes every few days rather than all at once. How to wake up earlier has a two-week plan for exactly that.

Plan the day around the dip

Put your hardest work in the hours when you are sharpest, which for many people is the morning, and keep the early afternoon for meetings, email and routine tasks. You stop fighting the dip and start using it.

Eat a lunch you could walk after

Some protein, some vegetables, a portion that doesn't leave you heavy. Then actually walk, even for ten minutes.

Break up the sitting

Get up every hour or so, and take a proper break mid-morning and mid-afternoon. Every trip to refill your water counts.

When should you see a doctor about daytime sleepiness?

Feeling dozy after a short night is normal. These are not, and are worth raising with a doctor:

• You fall asleep when you don't mean to, in meetings, on the sofa mid-conversation, or worse, while driving.
• You feel sleepy most days despite regularly getting seven to nine hours.
• Someone tells you that you snore loudly, gasp or stop breathing in your sleep.
• You often wake with a headache or a dry mouth, or never feel refreshed.
• The sleepiness came on recently without an obvious reason, or comes with low mood, weight changes or other new symptoms.

Never drive when you feel drowsy. Pull over somewhere safe and rest.

Help from the notch

Notchpals can't sleep for you, and it doesn't track your sleep. It works on the two causes above that happen at the Mac: sitting still all afternoon, and staying up too late. A Movement character in your crew gets you out of the chair when you have been in it for most of an hour, and once each early afternoon suggests a short walk. Nick, the fluffy white spitz, is one of them, and he has firm views on walks.

NickTen minutes outside. Sniff something. Tell me about it after.

At night a Sleep character works from the bedtime you set in Settings: a nudge in the hour before it, then a second visit if bedtime comes and goes with you still at the keyboard. Snooze, the sloth who believes every hour is nap hour, is an unlikely messenger for that one.

SnoozeShhh... it's past bedtime... the emails can wait till morning...

Press Done and Snooze sees you off. It takes your word for it, so whether you actually went to bed is up to you. On a busy evening, though, noticing the time is often the part that goes wrong.