Wake up to what's really causing your sleepless nights

Finding yourself wide awake in the early hours of the morning gets more usual as we age. TANITH CAREY speaks to experts to find out why – and offers some advice on fine-tuning your sleep routine...

- Edited by MATT NIXSON & HANNA GEISSLER

It's that time of night again. It's 3am and you're wide awake, hit with a wave of dread as you blink at your phone and see there are still hours to go until morning. Only you can't sleep at all now because you're panicking about getting enough rest to function the next day. Your heart starts to race, thoughts spiral, and you're trapped in a vicious circle. Sleep expert Professor Russell Foster explains just why these early-morning "witching hour" wakings happen - and how to sleep through the night.

IT'S A NATURAL PART OF YOUR SLEEP CYCLE

You may not realise it but all your life you've woken up several times a night as part of your normal sleep cycle. Most of the time you don't notice these “micro-arousals”, which occur as you drift in and out of deeper and lighter sleep.

But as we get older, changes in our sleep and stress hormones make it more likely we will wake - and also make it harder for us to get back to sleep.

By later life, one in three older adults over the age of 60 say they wake too early or struggle to stay asleep regularly, according to a study in the journal Sleep.

Foster, professor of circadian neuroscience at the University of Oxford and author of Life Time: The New Science of the Body Clock, explains: "It's not waking up in the night that's the issue. It's the difficulty of going back to sleep that's the problem."

WHY WOMEN WAKE IN THE NIGHT

As women approach menopause, hormonal shifts make "witching hour" wake-ups more likely. One is the gradual drop in the female sex hormone oestrogen, which plays a key role in helping women achieve deep sleep, so it becomes more erratic.

As oestrogen also regulates body temperature, when it starts to fall it can result in temperature spikes, such as hot flushes. When this happens in the middle of the night, the brain can interpret the temperature increase as a signal that it's time to get up.