Why do you stop feeling tired the second you get into bed?

Sound like you? You might have one of the most common sleep disorders

Why is it that the second you cosy down to catch forty winks, you’re wide-awake? (Getty Images/iStockphoto)

We’ve all been there. You’ve been struggling to stay awake all day, warding off yawns with countless cups of coffee and unable to think of anything but hitting the hay.

But, the second you cosy down to catch forty winks, you’re wide-awake.

It turns out, that lying in bed unable to fall asleep is actually a disorder called conditioned or learned arousal and is considered one of the most common sleep problems.

So why does it happen?

According to sleep-medicine specialist Philip Gehrman, an assistant professor of psychiatry at the University of Pennsylvania, it’s because something in your sleep environment has signaled to your brain that getting into bed should “arouse” you rather than send you to sleep.

“If someone is a good sleeper, then each night they probably get in bed and fall asleep. So when they get into bed it triggers this auto response of sleepiness,” Gehrman told TIME.

“But if you spend night after night tossing and turning not being able to fall asleep, then your body associates that with your bed instead.”

Thanks to the domination of smartphones, tablets and laptops in our lives, tossing and turning in bed has become common for many but other factors like thinking about work or worrying can also disrupt your sleep.

The most obvious way to treat the condition is to not have any screen time or bright lights in the hour before bed. This is because light, especially the blue light given off by screens, suppresses the production of melatonin, a chemical that helps your body to sleep.

Similarly, experts at Psychology Today recommend taking regular exercise during the daytime, avoiding caffeine, alcohol and tobacco in the evening and not forcing yourself to sleep.

Instead, if you’re having trouble nodding off, get up and do something relaxing until you feel ready to go to sleep.

If all else fails you could try cognitive behavioural therapy or CBT-I which involves regular visits to a clinician who will help to change your sleep schedule and bad habits.