Insomnia is defined as difficulty getting to sleep or staying asleep for long enough to feel refreshed the next morning. Most of us will have experienced disrupted sleep and will know how it feels when we can’t seem to fall asleep. It may be that you're thinking about the next day or have had a coffee too close to bedtime. Perhaps you found it easy to fall asleep but continue to wake up through the night. Either way, a rough sleep can leave you feeling drained and irritable the next day. Those who suffer from insomnia will experience these feelings regularly.

It is estimated that a third of people in the UK have episodes of insomnia during their lives. While it can affect anyone at any age, people over the age of 60 and women appear to be more susceptible.