Robert Winston explores the state of the nation's sleep.

See what a group of poor sleepers discover when they get tested in the sleep lab. Robert reveals the best solutions to the common problems.

Your personal sleep profile
Whether you have trouble sleeping or not, take the Sleep Profiler and get tailored advice on how best to optimise your sleep.

Sleep problems and sleep advice
Get to the root of some common and not so common sleep problems. For a list of foods that could be keeping you awake go to sleep advice.

Why do we sleep?
What would happen if we didn't sleep? Find out more about the science behind sleep, from REM to the sleep cycle.

What's your natural rhythm?
Could your sleep pattern be at odds with your DNA? Take the Circadian Rhythm Test and discover your natural 24 hour body clock.

Sheep dash!
Tiredness can affect your reaction times. See how alert you are with this game and test the impact of a cup of tea or coffee on your performance.

Face Memory Test
Are you too tired to remember? 'Executive skills' such as memory are the first to go when you're tired. See how you score.

Sleep Quiz
Test your knowledge with the top ten most fascinating and weird sleep facts.