Are you finding it hard to get out of bed after the summer holiday ends? This could be because of changes to your sleep pattern. Sleep patterns are the different stages of sleep.

The four stages of sleep are based on whether our eyes are moving – rapid eye movement (REM): light non-REM sleep stages 1 and 2, deep non-REM sleep, and REM sleep. We go through these stages several times every night (see graphic).

Non-REM sleep has three parts: falling asleep, light sleep and deep sleep. During this time, brain waves slow down, and muscles slowly relax. During deep sleep, our body rests and repairs itself.

Each night, we also spend about two hours dreaming. This usually happens during REM sleep. Children need between nine and 12 hours of sleep every night. If you do not get enough sleep and wake up during non-REM sleep, you will feel extra sleepy.