Having problems sleeping? I'm sure you're not alone, many people experience insomnia at some point in their lives.

This is part one of five issues that can cause it.

A disrupted routine

Our body clock reacts to light and dark even when are eyes are closed. The aim being to synchronize our body to something known as the 'circadian rhythm, which could be described as our best natural state as human beings. The sleep hormone is called melatonin and during daylight it's production is reduced causing us to feel more awake and alert.

This means that if we go to bed later than usual or get up earlier we don't get as much of the deep sleep, and the REM sleep that follows it, as we need and hence feel tired.

So, try to avoid both too many late nights partying and too many early starts! Easy to say, right?