Sleep Science: What are the Stages of Sleep?

Sleep is incredibly important for our wellbeing, but that doesn’t mean most of us have any idea about what it really is and how it can assist us. For that reason, lots of us don’t prioritise it. To help us understand, there’s been lots of research into sleep, with particular emphasis on ways to get the best quality of sleep. We now have a good understanding with regards to the different stages of sleep, and your brain and body go through a specific cycle of these stages as you snooze. Each stage of sleep plays a super important role in helping us to achieve positive wellbeing. In this article, we will discuss the sleep science behind these stages, so that you can understand the job of each.


There are conventionally four categories of sleep; wakefulness, light sleep, deep sleep, and REM sleep. Awake time is the natural break in sleep our body needs. This can happen throughout the night, usually at short intervals, and is included in the period we have in bed before and after we go to sleep. It can sometimes be assumed that we should remain asleep throughout the full night, with no wakeful periods. In fact, having several brief awakenings is completely normal and a natural part of our sleep cycle.

Light sleep

Light sleep can be also commonly known as stages 1 and 2. These are the first two stages of sleep, when our body begins to transition into sleep. Have you ever experienced your muscles jerk just as you drift off? This is really common in these stages. It’s also a lot easier for us to be disturbed in these stages, so waking up in light sleep is more likely than in other stages. Light sleep supports your muscles to relax and is the stage in which your respiration and heart rate slows down. The main focus of light sleep is to guide your body into the deeper stages of sleep.

Deep sleep

Deep sleep is also known as stages 3 and 4 of sleep. Through the term ‘deep sleep’, you may be able to guess that this is when it is harder to be disturbed or woken. If we are woken in these stages, we are likely to feel groggy or disoriented. These stages of sleep are essential in supporting our body with rest and restoration. Lots of important things happen in deep sleep. Our blood pressure drops during these stages, and our body focuses on muscle growth and repair. Ever wonder why our muscles after a heavy workout feel much better after a few great night’s sleep? These stages are why. Blood flow will increase to our muscles and cell repair, and tissue growth will occur. The brain also flushes waste during these stages. This will show long, slow brain waves on a sleep monitor.

REM sleep

REM stands for rapid eye movement, which is what happens during this stage. You can observe people’s eyes flicker during this time. This is the stage where our respiration and heart rate increases. Most importantly, it is the stage in which we dream. Dreaming is important, as it helps us to process our emotions from the day. Ever wonder why we don’t act out our dreams? Our body becomes immobile during this stage to stop us from putting ourselves in danger. This stage not only helps us process our emotions, it is also incredibly beneficial for storing memory, learning, and problem solving. Got a lot of learning to do? Have a good night of sleep, and this could be extremely beneficial.

What does a normal cycle look like?

A normal cycle can differ significantly from person to person. On average however, a person can go through all of the above stages over a 90-minute cycle. Going through this cycle can happen around four to five times throughout the night, depending on how long we sleep. Usually, each cycle moves through each stage of sleep, starting with stage 1 and ending with REM. It will then repeat this cycle over and over until it reaches its final cycle. Cycles earlier in the evening ten to focus more time on deep sleep, whilst those later in the night tend to focus more on a higher proportion of REM sleep. Your body may choose to skip deep sleep altogether in the later stages. When you take an average look at the different cycles, we spend the majority of time sleeping in the lighter stages.

Hugh Beds

There you have it. That is the basic science behind your sleep.

At Hugh beds, we really understand your sleep related needs. We know the common sleep problems many of our customers face and have worked hard to fix these issues using the expertise of our amazing team. We have created the very best mattresses made from the latest scientific materials to eliminate common sleep problems. We have a range of unique mattresses to suit your needs. To check out our amazing mattresses and their brilliant benefits, please visit products page.