If you use a sleep tracker app you may notice it says you’ve woken up several times in the night. This isn’t a problem – it’s perfectly normal to wake several times a night and most of the time you won’t even realise you have.

After each 90-minute sleep cycle, we come to a point of partial awakening. As the night progresses, the need to sleep lessens and so we spend more time in lighter sleep; so brief awakenings can feel more noticeable.

Sometimes you remember these periods (like checking the time before dozing back off), whereas other times you don’t. But whether you rememberthem or not, you should fall back to sleep easily by yourself.

You’re more likely to wake if conditions have changed whilst you’ve been asleep. For example, if you fall asleep watching TV and it turns off, you’re more likely to fully wake up during a partial waking because the light and sound conditions in the room have changed.

The key thing to learn from this is that conditions should be consistent all the way through the night for you to reduce your chances of waking up once you have nodded off.

We all have an internal body clock that runs roughly on a 24-hour cycle, sometimes referred to as a circadian rhythm.

Our body clock takes its cue from the light and dark (the biggest cue being sunrise and sunset) to keep us to this rhythm and help us feel sleepy at bedtime and awake in the morning.

Certain factors affect your body clock and the times you feel sleepy. For example, we talk about “morning larks” for those who are more awake in the morning or “night owls” for those who are more wakeful late in the evening.

Whether your a morning-person or a night owl is often something that is genetically programmed, so if your parents tend to be one or the other you are more likely to follow that pattern as an adult. It can help to know which camp you fit into when trying to improve your sleep.

Melatonin is a hormone that occurs naturally in our bodies when it gets dark. It’s produced at night-time to help us go to sleep.

Light is a common sleep ‘robber’ because when light signals enter the eye, this sends a command to the brain to stop producing melatonin.

This is why it is a good idea to go to bed in a dark environment and to dim the lights in the run up to bedtime.

Right now, we have more exposure to artificial light than ever before. This disrupts our body clock: keeping us alert and feeling less sleepy.

In particular, melatonin production is interfered with by screen activities like watching television or reading on your phone. The light from the screens will stop the melatonin being produced as effectively – meaning your body won’t get the signal to help it feel sleepy and you may find it harder to get to sleep.

In addition to your circadian rhythm, sleep is also regulated by your sleep/wake homeostasis. This tells you when you are tired and need to rest.

You build up a need for sleep during the day (sleep pressure) and then, when bedtime comes, you are tired and ready to rest. Think of it like a battery.

In the morning, after a good night’s sleep, your battery is fully charged. As the day goes on your battery depletes. If you have a nap, this will charge it up a little more, meaning you may not be quite as tired at bedtime.

For some teens, a short, early afternoon nap may be helpful in improving alertness and it’s much better for supporting your body clock than having a lengthy lie in.

However, naps shouldn’t be used as a substitute for a getting a good night’s sleep. Limit power naps to around 20-30 minutes for maximum impact. Any longer and they may leave you feeling groggy and interfere with your night-time sleep.