London - Your eyelids have become irresistibly heavy, you feel your limbs losing strength as you sink back into your chair.
You’re not alone - 34 percent of us fall asleep during the day without intending to, or struggle to stay awake while doing things, according to the Great British Sleep Survey. From the snorer at the theatre to the noble men and women nodding off in the House of Lords, we just can’t keep our eyes open.
So what’s causing your daytime drowsiness - and should you fight the urge to snooze? Here, experts reveal the latest thinking.
WE’RE PRIMED TO FEEL DOZY AFTER LUNCH...
The natural energy slump in the afternoon is down to our internal body clock. The moment we first wake up our bodies start releasing the sleep hormone melatonin in preparation for sleep.
Meanwhile, the part of our body clock that drives wakefulness tends to build in the late afternoon. There may be a window of time when the drive for sleep has been building for hours and the drive for wakefulness has not yet kicked in.
‘We’re not being told yet to keep awake by the body clock, so we feel like dozing,’ says Russell Foster, professor of circadian neuroscience at Oxford University.
Genes may play a part, says Dr Guy Meadows, director of The Sleep School in London. ‘People will know if they’re an owl or a lark. I’m a lark, wide awake at 6am, but come the afternoon I’m prone to feel like I need a doze. Owls are more likely to doze in the morning.’
...BUT WORRY IF YOU FEEL SLEEPY ALL DAY
If you find yourself nodding off uncontrollably or feel sleepy all day, you’re probably sleep deprived. ‘Being dozy all day is indicative of disturbed or inadequate sleep,’ says Professor Jim Horne from the Sleep Research Centre at Loughborough University.
If you’re not getting the required amount of sleep (which for adults is between seven and eight hours), the next day will reflect on the previous night.
Your first port of call should be to tackle anything that’s disturbing your sleep, such as checking your emails in bed, says Dr Meadows. ‘Get such distractions sorted, and you’ll often find the urge for daytime dozing goes.’
Excessive sleepiness, napping or falling asleep in the daytime is often a sign of a sleep disorder such as bruxism (teeth grinding) or insomnia - the Epworth Sleepiness Scale questionnaire helps assess this.
This measures tiredness by asking how likely you are to doze in situations such as reading, so you can work out if you need help from a GP or sleep clinic. Find the questionnaire at britishsnoring.co.uk.
IT COULD BE YOUR MEDICINES
Some medications can cause daytime drowsiness - these include anti-depressants, anti-histamines and cold remedies.
Products containing older sedating antihistamines such as diphenhydramine are most likely to cause drowsiness. Doxylamine (found in Syndol and Propain Plus) or promethazine (Night Nurse, Avomine) can cause sleepiness, too.
Some people have a genetic susceptibility to these ingredients that makes them more prone to this effect. Taking medication at night may cause drowsiness the next day as some drugs take hours to disappear from the body.
...OR BEING A WOMAN
‘Women suffer more from insomnia than men at a ratio of 65:35,’ says Dr Meadows. ‘This is partly because women have more hormonal disruptions affecting their sleep and they also tend to worry more. This not only means that their minds are more likely to race at night, but it could also result in higher levels of the stress hormone cortisol, which can make it harder to fall asleep.’
However, daytime dozing is more common among men than women - and more common among lower earners than higher earners, according to a 2009 survey from the Pew Research Centre in the U.S.
The survey of 1,500 adults found 38 percent of men and 31 percent of women said they’d taken a nap in the past 24 hours. Among those over 50, 41 percent of men doze, while just 28 percent of women do.
Among people earning more than £62,000, 33 percent said they doze regularly, while 42 percent of those making less than £19,000 nap during the day.
...OR YOUR AGE
It’s a common misconception that older people fall asleep in the day because they need more sleep. In fact, it’s largely because they don’t get enough sunlight that helps them stay awake.
‘Also, as we get older our body clock is likely to get less sensitive to light and its alerting factors,’ says Professor Foster.
‘Then there’s the fact older people suffer more from bad backs, arthritis and weaker bladders that mean they don’t get a good night’s sleep.’
BEWARE THAT WEEKEND LIE-IN
Many of us can’t resist a lie-in on the weekends, but be warned: by getting your sleep cycles out of rhythm, you could be putting yourself at risk of daytime tiredness. ‘Most tiredness happens because we are bad at sticking to regular bedtimes,’ says independent sleep expert Dr Neil Stanley.
The body has an accurate natural clock - this is why we sometimes wake up just before our alarm goes off. If the body clock is in rhythm, in the hour before waking we start to enter a lighter cycle of sleep known as REM.
‘Being woken abruptly outside of REM sleep, such as by an alarm clock, can leave us feeling groggy from this deep sleep we’ve been in,’ says Professor Foster.
And if you’re sitting on the train 30 minutes later, you might feel a strong urge to doze - to finish off your sleep properly so you wake at the right part of it.
SNORING CAN BE A DANGER SIGN
If you feel sleepy in the day no matter how early you go to bed at night, it could be a sign of Obstructive Sleep Apnoea - especially if you snore, too. The condition affects up to 4 percent of the population, says sleep specialist nurse Beccy Mullins.
‘It’s common in overweight people. As they sleep, their airways start to collapse, often starting with loud snoring when the airway vibrates as it narrows, before total collapse, and they stop breathing for anything from ten to 60 seconds.
‘Their oxygen levels drop so low the brain initiates breathing to begin again. Sufferers are not usually aware of the problem, but they don’t get refreshing sleep due to the interruptions.
‘Despite thinking they’ve had a good night’s sleep, they wake feeling tired, un-refreshed and it persists throughout the day, day after day.’ Long-term, it’s been linked to a greater risk of high blood pressure, type 2 diabetes, heart attack and stroke. As well as loud, persistent snoring, it’s more likely in people who are overweight - seek advice from a GP.
Treatment is with Continuous Positive Airway Pressure - you wear a mask over the nose at night, while a bedside blower unit pumps in air to ensure the throat remains open.
STEER CLEAR OF JACKET POTATOES
So if it’s not related to a medical problem, how can you tackle the sleepiness? If you’re facing a big meeting and are worried you’ll get that familiar urge to nod off, Dr Meadows advises getting lots of natural light by going outside.
‘This informs the brain it’s still daytime and releases cortisol, the waking hormone.’
Think about what you eat, too. ‘If you have a high-carb lunch, such as a jacket potato and beans, blood sugar levels will go up but then fall,’ says Dr Meadows. ‘We enter a state of hypoglycemia, which is a deficiency of glucose in the bloodstream.’
Colin Espie, professor of clinical psychology at Glasgow University and director of the Sleepio Clinic, advises drinking plenty of water: ‘If dehydrated, we slow down to conserve the hydration we have.’
FINALLY, OPEN YOUR WINDOWS
‘Your environment might not be conducive to wakefulness, such as if it’s hot or stuffy,’ says Professor Espie.
‘Or you’re under-stimulated with not enough to do. If these factors are combined with when you’ve hit your body clock low point, you are vulnerable to dozing.’ - Daily Mail