There are 4 stages of sleep. These are:
- stage 1, mild sleep;
- stage 2, moderate sleep;
- stage 3, deep, slow-wave sleep; and
- stage 4, REM (deep, dream sleep.)
Stages of Sleep Explained
When you begin to fall asleep, the rapid, wild brain waves of wakefulness ease up, and you enter stage 1, mild sleep. Some people can have vivid hallucinations as they drop off to sleep. These hallucinations include visions of people or animals, sensations of falling or flying, or even impressions of scent or touch. These can be normal, but people who have a lot of these all the time could be narcoleptic.
Then stage 2, moderate sleep, begins. There is not much significance to mild and moderate sleep stages. Stage 2 may last a while after falling asleep- 50 minutes or so.
If there are no distractions, you should advance to stage 3, the deep, slow-wave sleep where the body is quiet and has little to no movement. Your brain waves change from a choppy sea into the kind of big, rolling swells of waves that sweep in after a storm. These are called delta waves which start in the frontal lobes and roll back to the back of the brain. With deep sleep, the brain consolidates information learned that day like a computer when updating files. It decides which memories to file and which to trash. The body produces growth hormones and many other hormones during deep sleep that are used for healing and helping with emotions. We also produce cytokines during deep sleep, which help strengthen the immune system.
After about 90 minutes of deep sleep, your brain takes a sharp turn into stage 4, REM sleep. REM sleep consists of dreams, and here the brain is quite active. We think that dreams are also a vital mechanism our brains use to process memories and emotions. During dreams (REM sleep), visual perception, movement, autobiographic memory, and emotional processing are highly active. Your big voluntary muscles like your arms and legs go limp. The body’s involuntary muscles, like your lungs and heart, still work and the eye muscles can still move. However, body temperature goes down, and you are usually paralyzed.
We have been led to believe that dreams help us process our emotions because those who dream of an actual traumatic experience (one that has happened to them already) recover more completely than those who don’t. One to two percent of our dreams contain literal replays of the day, but up to 55% of our dreams revisit the day’s emotions.
The cycle of stages repeats about 4-6 times per night. The amount of stage 3, deep sleep, decreases toward morning, while REM sleep increases. It is common to wake several times during a good night’s sleep, although you may not remember it. Getting about 60-90 minutes of deep, slow-wave, and REM sleep is considered a good night’s sleep. We don’t know why sleep cycles in and out of these phases during the night, but we know it is necessary to sleep well.
Could you use some of the Benefits of Good Sleep?
If you have been experiencing problems with getting good sleep and have not resolved them, a functional medicine approach may help. Our providers can help you get to the bottom of what is causing your sleep troubles and resolve these. Good sleep makes a huge difference in your health and well being and addressing this can improve your quality of life. For more information about us or how we can help, Contact Us.