Sleep cycle

When you go to sleep, your body goes through different stages of sleep. These stages happen in a cycle, like going around in a circle.

The first stage is called light sleep. This is when you start to feel relaxed and your muscles start to loosen up. You can still be awakened easily during this stage.

The second stage is a bit deeper sleep than the first stage. Your body temperature and heart rate start to lower down.

Then comes the deep sleep, which is the most restorative part of the cycle. This is when your body tries to heal and grow. It's tough to wake you up during this stage.

Finally, there is something called 'REM' sleep, which stands for Rapid Eye Movement. During this stage, your brain becomes very active and you start to dream! Your eyes might twitch underneath your eyelids. This stage is also tough to wake you up from.

Once you go through all the stages, you start the cycle all over again. On average, a full sleep cycle is about 90 to 110 minutes long. It is important to complete a few cycles each night to have a good quality sleep.