Excessive Daytime Sleepiness: Causes, Checks and When to Get Help

Excessive daytime sleepiness is when you struggle to stay awake during the day, nodding off in meetings, on the couch or, worst of all, behind the wheel. Everyone has a sleepy afternoon now and then. Feeling this way most days is a sign that something is getting in the way of your sleep or your alertness. This guide covers how sleepiness differs from fatigue, the common causes, a quick self-check, the tests a doctor may use, safety on the road, and when to see your GP.

The short answer: excessive daytime sleepiness means a strong urge to fall asleep when you want to be awake. The most common cause is simply not getting enough sleep, but poor-quality sleep, shift work, sleep apnoea, mental health problems, other medical conditions and sleep disorders such as narcolepsy can all cause it. Start by giving yourself a regular, long enough sleep window for two weeks. If you're still sleepy, see your GP. Never drive when you're drowsy, and an alarm is not a treatment for sleepiness.

This guide is general information, not medical advice.

Sleepiness is not the same as fatigue

The two words get used interchangeably, but doctors treat them differently.

• Sleepiness is the desire or need to fall asleep. The Sleep Health Foundation defines it that way, and notes it may or may not come with feeling tired (source). If you sit still, you drift off.
• Fatigue is a feeling of tiredness or low energy that doesn't get better with rest. Healthdirect describes people calling it weakness, sleepiness or "feeling flat" (source). You may feel drained but still not be able to nap.

Knowing which one you have helps your GP. A useful question to ask yourself: if I lay down in a quiet room right now, would I fall asleep? If the answer is often yes, that's sleepiness.

Common causes

The Sleep Health Foundation lists these main causes of excessive daytime sleepiness.

Cause	What it looks like
Not enough sleep	Late nights, early alarms, sleep pushed aside for work, study or screens
Poor-quality sleep	Enough hours in bed but broken, light or disturbed sleep
Physical health conditions	Heart problems, diabetes, thyroid problems, arthritis, or waking often to pass urine
Mental health	Anxiety and depression can both disturb sleep and alertness
Shift work	Sleeping against your body clock
Breathing problems in sleep	Obstructive sleep apnoea, often with loud snoring
Sleep disorders	Narcolepsy and other conditions that affect alertness directly

Medicines can play a part too; healthdirect notes some medicines cause fatigue. Don't stop a prescribed medicine on your own, but do ask your GP or pharmacist.

If you're sleeping eight hours and still waking unrefreshed, our guide on being tired after 8 hours of sleep goes into the likely reasons. Snoring with pauses in breathing points towards sleep apnoea. Sudden sleep attacks, especially with muscle weakness when you laugh, point towards narcolepsy.

A two-week self-check

Before you see your GP, it's worth ruling out the most common cause: not enough sleep. Try this for two weeks and write down what happens.

1. Pick a fixed wake time and keep it every day, including weekends.
2. Count back to give yourself a sleep window that matches what you need. If you're not sure what that is, see how much sleep do I need.
3. Protect the window. Screens down, lights dim, caffeine finished early in the day.
4. Log it. Note when you went to bed, roughly when you fell asleep, when you woke, and how sleepy you felt at mid-morning and mid-afternoon.

If the sleepiness lifts, you were short of sleep. If it doesn't, take the log to your GP. It's the kind of detail that speeds things up.

How doctors assess sleepiness

Your GP will ask about your sleep, health, mood and medicines, and may order blood tests to look for things like iron deficiency or thyroid problems, which healthdirect lists among the medical causes of fatigue.

The Sleep Health Foundation notes that sleep specialists use the Epworth Sleepiness Scale, a short questionnaire about how likely you are to doze in everyday situations, as a screening tool. If needed, a specialist may arrange an overnight sleep study and sometimes a Multiple Sleep Latency Test, a series of daytime nap opportunities that measures how quickly you fall asleep.

Sleepiness and driving

This is where daytime sleepiness becomes dangerous. The Sleep Health Foundation says it is unsafe to drive while sleepy, and warns against ignoring sleepiness when driving or operating machinery.

Its drowsy-driving guidance lists warning signs including heavy eyes, wandering thoughts, missing signs, drifting out of your lane and head nodding, which it calls end-stage drowsiness that means you are already having micro-sleeps. If you notice any of these, pull over somewhere safe. A nap of 15 to 20 minutes, then a short walk, is the recommended stop-gap (source). Winding down the window or turning up the music doesn't fix it. See drowsy driving in Australia.

When to see your GP

See your GP if:

• you're sleepy most days and a fortnight of proper sleep hasn't helped
• you've nodded off while driving, or come close
• you snore loudly, or someone has seen you stop breathing in your sleep
• you fall asleep suddenly at odd times, or your knees buckle when you laugh
• the sleepiness comes with low mood, weight changes or other new symptoms.

Healthdirect also advises seeing a doctor if fatigue lasts more than two weeks and isn't getting better.

Where the Sovune Nudge fits

We make the Sovune Nudge, a silent vibrating wristband alarm, so we're not neutral. To be clear, a vibrating alarm is not a treatment for excessive daytime sleepiness or any condition that causes it. It's simply a way to wake at a consistent time without disturbing anyone else, which helps when you're working on a regular sleep window.

• Wakes you with vibration on your wrist, starting gently and building through three intensity levels.
• Each alarm runs for a full minute, stepping up through the levels, and you can switch it off sooner.
• Three separate alarms, set on the band itself, with no app or phone.
• Up to 14 days of nightly use per charge.

It comes with a 30-day money-back guarantee.

Quick answers

What is the most common cause of daytime sleepiness? Not getting enough sleep. Try two weeks with a regular, long enough sleep window before looking for other causes.

Is being sleepy the same as being tired? Not quite. Sleepiness is the urge to fall asleep. Fatigue is low energy that rest doesn't fix. Your GP will want to know which you have.

What is the Epworth Sleepiness Scale? A short questionnaire about how likely you are to doze in everyday situations. Sleep specialists use it as a screening tool.

Should I drive if I feel sleepy? No. Pull over somewhere safe and take a 15 to 20 minute nap. If it happens often, see your GP.

For every type of silent alarm compared, see our complete guide to vibrating alarms in Australia.

See the Sovune Nudge →