Some people not only find their memory is affected but it can also have an effect on their mental health
Fiona Callingham Lifestyle writer
00:01, 06 Dec 2025
A doctor warned that a common sleeping habit could lead to long-term damage(Image: Getty)
A neurologist has delivered an urgent warning about sleep, suggesting that one common nightly habit could prove “dangerous”. The expert cautions that this behaviour not only poses immediate health risks but may also increase the likelihood of developing dementia.
We’re all familiar with how crucial sleep is. Insufficient rest leaves us exhausted, irritable, and generally under the weather the following day.
However, what many fail to appreciate is the more severe toll it can take on overall health and wellbeing. In a clip shared on social media platform TikTok, neurologist Dr Baibing Chen cautioned that “consistently” getting fewer than seven hours of sleep each night could prove harmful.
Dr Chen, who goes by Dr Bing online, stated: “Here are reasons why consistently sleeping less than seven hours a day is so dangerous for you.” He highlighted that even a single night of inadequate rest can produce effects comparable to being drunk.
“If you’re awake for 17 hours or more, your reaction time, focus and judgement drop to the level of someone with a blood alcohol level of 0.05 per cent,” he said. “That’s the legal limit for driving in some countries, and if you’re awake for longer than that, you’re pretty much acting like you’re drunk.
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“You don’t want that for yourself and you definitely don’t want that in your doctors.” He then elaborated on the longer-term dangers.
He explained: “During deep sleep, your glymphatic system, which is your brain’s cleaning system, flushes out the toxins, including a protein called beta amyloid, which is the same protein that builds up in Alzheimer’s disease. And when you consistently cut your sleep short, those proteins can slowly accumulate, which then raise your long term dementia risk.”
Sleep is also crucial for memory function. Dr Bing noted: “People don’t realise how much your memory is dependent on your sleep. New information from your day is stored temporarily in your hippocampus, but it only transfers to your long term memory during deep sleep.
“So without enough rest, your brain fails to save what you’ve learnt throughout the day, which is why sleep deprived people forget details and make more mistakes.”
Beyond this, there are significant implications for mental wellbeing. He continued: “If you consistently don’t get enough good quality sleep, that will weaken the communication between your prefrontal cortex, which is your logic centre, and your amygdala, which controls your emotions. And that’s why you can become more anxious, more irritable, and more impulsive after a short night.
“We live in a society that glorifies overworking but burning out your brain isn’t a sign of strength and lacking sleep isn’t something to brag about – it’s something that we need to fix.”
How much sleep you need
The NHS explains that everyone needs different amounts of sleep. On average:
Adults need seven to nine hoursChildren need nine to 13 hoursToddlers and babies need 12 to 17 hours
The NHS says: “You probably do not get enough sleep if you’re constantly tired during the day.” To improve your sleep the NHS recommends you:
Go to bed and wake up at the same time every dayRelax at least one hour before bed, for example, take a bath or read a bookMake sure your bedroom is dark and quiet – use curtains, blinds, an eye mask or ear plugs if neededExercise regularly during the dayMake sure your mattress, pillows and covers are comfortableDo not smoke or drink alcohol, tea or coffee at least 6 hours before going to bedDo not eat a big meal late at nightDo not exercise at least four hours before bedDo not watch television or use devices, like smartphones, right before going to bed, because the blue light makes you more awakeDo not nap during the dayDo not sleep in after a bad night’s sleep and stick to your regular sleeping hours instead
You should see a GP if:
Changing your sleeping habits has not helped your insomniaYou’ve had trouble sleeping for monthsYour insomnia is affecting your daily life in a way that makes it hard for you to cope