The Different Stages of Sleep and How They’re Important

If you wake up most mornings feeling exhausted, there’s a chance you aren’t getting a full 7 to 9 hours of rest each night. When you go to bed, your brain begins to cycle through all the different, important stages of sleep. However, things like a neighbor’s barking dog, having to use the bathroom, or even sleep apnea can all interrupt your slumber and prevent you from feeling refreshed in the morning. Here’s how each stage of the sleep cycle affects you every night, and how something like sleep apnea can influence the quality of your sleep.

The Early Stages: Light Sleep

As you fall asleep, your eye movements gradually begin to slow down, and you enter the first stage of light sleep. Your body remains alert to some degree, and certain noises and stimuli can still disturb and wake you up. However, you should only remain in this state for the first few minutes.

Next, you’ll enter the second stage of light sleep, and your brain will start producing sleep spindles. These are special brainwaves that protect you from being woken up early. In this stage, you’re still lightly asleep and will remain so for roughly half of the entire cycle.

The Later Stages: Deep Sleep and REM Sleep

Once you finally reach the deep sleep stage, it is more difficult for you to be woken up. Your body will begin to repair any muscles or tissues that were damaged during the day, and it’ll also produce protective cytokines (small proteins) that help the immune system and restore cells’ energy levels. Deep sleep is also particularly important in the development of children and teenagers.

REM stands for rapid eye movement, and it is the final stage of the sleep cycle. Underneath your eyelids, your eyes quickly jerk and twitch in various directions, which signals that your brain is consolidating and processing new information it learned from the previous day (this is important for memory retention). Your body will also experience an increased heart rate, higher blood pressure, and sometimes shallow, irregular breathing—although this is perfectly normal and healthy.

The Value of Uninterrupted Sleep

A sleeping disorder, such as sleep apnea, can interfere with the body’s ability to recover every night. Sleep apnea causes you to have brief, frequent pauses in your breathing while you’re asleep—when this happens, your body must partially wake up to restore normal respiration, and the brain is kicked out of its cycle. If you aren’t spending enough time in deep or REM sleep, your physical health and mental capabilities will be affected.

If you’re tired all the time, chances are you’re missing out on at least a few stages of the sleep cycle most nights. It might be time to talk to your doctor so you can get back on track and back to bed.

About the Author

Dr. Eric Coontz received his DDS from the Loyola University School of Dentistry in Chicago and also holds a Master of Science in Oral Biology. He maintains memberships in several prestigious organizations such as the American Sleep and Breathing Academy (Diplomate status), the American Academy of Sleep Medicine, the Academy of Associate Sleep Professionals, and others. He brings over 45 years of experience to his field and has spent countless hours specializing in dental sleep medicine and TMJ therapy. If you would like to contact Dr. Coontz, or if you have questions about sleep apnea treatment, he can be reached at his website or (505) 433-2107.