4 Stages of Sleep

If you’re unsure what happens while you’re sleeping, you’re not alone. After all, as your body goes through the stages of sleep you are … well, asleep. Still, it’s important to understand the stages of sleep and why they’re so darn important for your overall health and wellness.

Every night, you take a rollercoaster ride through the various stages of sleep. You may not be aware of it, but your body and brain are active. Here are the different stages of sleep and how each plays a distinct role in your overall health and how you feel when you wake up the next day.

The Four Stages of Sleep

There are four stages of sleep — three stages of non-REM (rapid eye movement) and one stage of REM sleep. Each is unique and plays a vital role in helping you to maintain both your physical and mental health.

Stage 1

That wonderful feeling of starting to drift off to sleep is stage 1 — and it generally only lasts for a few minutes.

Throughout this stage, your breathing and heartbeat slows, your muscles begin to unwind and relax, and your brain begins to produce theta and alpha waves.

Stage 2

In this next non-REM stage, you sleep lightly before you enter deep sleep. It lasts between 10 and 25 minutes.

During this stage, your breathing and heartbeat slows down even more from stage 1, your eyes do not move, the temperature of your body drops, and your brain waves spike and fall, producing what sleep researchers call sleep spindles, which are brain waves researchers believe help to develop the cortex in the brain and aid in functions such as consolidating memory.

Stage 3

This is the last stage of non-REM sleep and the deepest of the sleep stages. This stage is commonly called delta sleep. During it, your body completes a variety of tasks that are essential to your health.

During this stage, it’s tough to wake you up because you’re so deeply asleep. Your eyes don’t move, your heart and respiration are at their slowest, your body is completely relaxed, and your cells regenerate as tissues grow and repair.

Stage 4

This is the REM sleep stage and begins about 90 minutes after you enter stage 1. This is the stage when you dream. As you cycle through the various sleep stages at night, this stage lasts only about 10 minutes the first time around. With each cycle, REM sleep increases, lasting about 60 minutes by the time you reach the final cycle.

In this stage, your eyes move rapidly, your heartbeat and breathing increase, your brain activity increases, and the muscles in your arms and legs are temporarily paralyzed. This is the stage when you dream and also when the areas of the brain associated with learning are stimulated.

When you sleep at night, you cycle through each stage multiple times. About every 90 minutes you cycle through the stages completely.

The Importance of Sleep

Everyone has spent a night tossing and turning, only to wake up in the morning feeling a little worse for wear. That’s because sleep has a huge impact on your brain function and getting enough of it is crucial for what is called brain plasticity, which is essentially your brain’s ability to adapt to the input it receives.

The rest of your body needs sleep as well. Those who don’t get enough sleep have higher risks for health issues such as depression, lowered immunity, headaches, high blood pressure, and a higher chance of infection. Plus, your metabolism relies on sleep since not getting enough shut-eye can impact your metabolism and blood sugar levels.

Sleep is important, which is why you need to make sure you’re getting the seven to nine hours per night you need. If you have physical issues that are impacting the quality and quantity of your sleep, then come in and talk with Dr. Zeh!