Definition: Generate an appropriate title for the given text. The generated title must be short and include the main topic of the text. The preferred titles are under fifteen words.
Input: By Rachel SchraerBBC Reality Check "Every year Santa Claus and his team of elves and reindeer stay awake for days and nights so he can deliver presents to children all over the world for Christmas - but he could be putting his and their health at risk," they say. Duly noted. But for the rest of us - does the festive period disrupt our sleep, and should we be worried about it? Of course, we can't speak for everyone, but there are a few things that might make December one of the less restful months of the year. Alcohol In December there is a clear spike in alcohol sales in the UK. If you are socialising and drinking more than normal, you could find that your quality of sleep is compromised. It is not only late nights and fewer hours of sleep making you tired - after drinking, the hours of sleep you do get may be less refreshing. That is because alcohol changes the normal sleep cycle. A drink before bed is sometimes associated with helping you nod off, because people who have been drinking can find themselves falling into a deep sleep more quickly. However, in the second half of the night, research suggests alcohol makes sleep shallower and increases wakefulness. Your heart rate will remain higher and it may mean less time is spent in "rapid eye movement" or REM sleep - the time when we dream. That stage of sleep is thought to have a role in repairing the body as well as consolidating memories and emotional processing. So overall, you could wake up less refreshed on the same number of hours' sleep than you would have without alcohol in your system. You might also find yourself less able to deal with emotional or stressful situations the next day. Social jetlag There is a genetic element to whether you tend towards being a night owl or a morning lark. It is called a chronotype and refers to what time someone tends to want to sleep and wake. If there is a big difference between this - think of it as your biological time - and your social time (the hours you actually have to sleep and wake to fit in with your work or social schedule), you can develop social jetlag. Like jetlag when you travel, it can make you feel groggy and affect your health. And this effect can be exacerbated during busy times when social demands mean you are getting fewer hours of sleep during the week and sleeping in more at the weekends to compensate. Late chronotypes or night owls are likely to have the biggest differences in sleep timing between their work and free days, and so will suffer most from the affects of social jetlag. Researchers think people who have later chronotypes are more likely to use stimulants and alcohol, and are more likely to smoke. As well as increased social demands at this time of year, family commitments can mean nights spent not in your own bed, perhaps with too many people crammed under one roof. Anxiety At a time of year when many people are rushing to finish work projects before the holidays, anxiety can be heightened. Many of us also have social commitments, family and financial pressures piled on top. The link between anxiety disorders and problems sleeping is well documented. This is not to say that feeling anxious from time to time is the same as having an anxiety disorder - but some of the short-term impacts on your body can be the same. Struggling to sleep when anxious also can set up a bit of a vicious circle, since sleep-deprived people might find it harder to regulate their emotions. Seasonal effects Shorter days and fewer hours of sunlight can make us crave more sleep. But it is not always possible to accommodate more hours in our daily routines, which can lead to feeling more tired in the day. For some people, mild seasonal depression makes them feel more lethargic and have less energy. In more extreme cases, seasonal affective disorder - thought to affect about one in 15 people in the UK - can have a serious impact on people's lives. How worried should I be? If worrying about not getting enough sleep is, well, keeping you up at night - you can be reassured that short-term sleep disruption won't hurt you - as long as you are not operating heavy machinery. If you are feeling sleep deprived and planning on driving a car, you should exercise caution, but it is not going to damage your health long term. What do you want BBC Reality Check to investigate? Get in touch Read more from Reality Check Follow us on Twitter

Do you sleep worse at Christmas?