Can’t sleep? Perhaps you’re overtired

Nerina Ramlakhan remembers when her daughter was a toddler, and how if she got too tired she would be unable to switch off. "There was a healthy level of tiredness," she says. "But if she went beyond that, she would be running on a kind of false energy. And then she wouldn't be able to switch off when she went to bed."

Overtiredness is recognised the world over in young children – but it is seemingly more and more common in adults. Dr Ramlakhan should know: she is a sleep psychologist and is increasingly seeing people who remind her of her little girl when she was younger.

There's certainly an irony that in our sophisticated, hi-tech, busy world we appear to be reverting to behaviour that we recognise and know how to treat in kids, but are somehow failing to deal with as adults. Overtiredness, sleep experts agree, is down to our always-on existence. In the past, says Ramlakhan, the author of The Little Book of Sleep, our days had naturally built-in downtime that gave us short snatches of rest. Today, that has disappeared for many of us. "We have become restless as a society – and that places more demands on us when we get into bed at night," she says. "We have lost the rituals and practices that gave us little respites during the day. In the past, you would go to the supermarket and, while you were waiting in the queue, you'd daydream, be a bit bored, look around. Now, any window like that will be filled by looking at your phone, answering some emails, sorting out your Amazon account."

You may think you are putting the time to good use – but that's not how your brain interprets it. There's a complex neurophysiology that requires breaks in tasks and concentration; if it's constantly bombarded, the brain becomes overloaded. The result, says Ramlakhan, is that it goes into what we might call survival mode: it assumes that something bad is about to happen, it ups the adrenaline and it puts out an urgent call for sugary snacks to provide quick-release energy.

And there's more: if your brain has become tuned to always reaching for the next thing to do, to never taking a moment to just pause and rest, then it will gradually become harder and harder to switch off at night. It's almost as if we're losing the ability to let go; and the biggest letting-go of all is falling asleep, which Ramlakhan describes as an act of trust. "There's a growing tendency to hold on, to keep on going, and it's manifesting in our sleep patterns as well. People say to me that they feel they're on the edge of sleep all night. They're getting up in the morning feeling exhausted. They say they keep waking up at night and can't get back to sleep. But it's normal to wake up at night; most of the time, we just go back to sleep."