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Understanding the Stages of Sleep


By Jaime Hollander

Getting good, restorative sleep at night is essential to feeling and performing your best. That's because sleeping soundly helps boost the body’s natural healing and repair processes, improves learning, memory and emotional well-being. So how to ensure you’re getting “good” sleep? Start by understanding how you sleep – the stages of sleep, sleep cycles and sleep quality, specifically. By understanding sleep stages, you’ll be able to better prepare for a good night’s sleep, and reap the physical and mental benefits the next morning and beyond.

Stages of Sleep

What is a “Sleep Cycle?”

According to the National Sleep Foundation, sleep is made up of multiple sleep cycles, also known as REM cycles. A single sleep cycle is 90 minutes long and includes periods of rapid eye movement (REM) as well as non-rapid eye movement (NREM) periods.

The typical adult will have about three to six sleep cycles in a single night. The first sleep cycle begins when a person falls asleep and lasts through the first REM period. Once that period ends, the next sleep cycle immediately begins with NREM sleep and continues through the close of that REM period.

What are the Stages of Sleep?

Our natural sleep cycle stages adhere to an alternating pattern of REM and NREM sleep – again, the 90-minute sleep cycles that makes up a typical night’s sleep. Within these cycles, your body will naturally transition through four stages of sleep. These include:

  • N1 (stage 1): This sleep stage is often described as the period between “awake” and “asleep.” Sleep during stage one tends to be fairly light.
  • N2 (stage 2): In stage two, sleepers become more and more unaware of surroundings and both breathing and heart rate normalizes. Body temperature also begins to drop in this stage as “real” sleep begins.
  • N3 (stage 3): Stage N3 is believed to be essential to supporting many functions throughout your body, such as restoring hormones essential for growth and development. Your body becomes relaxed, blood supply to your muscles increases, blood pressure drops and tissue growth and heart and blood vessel repair starts.
  • REM sleep: The last stage of a sleep cycle is REM sleep, which cumulatively takes up about 25 percent of a standard night’s sleep and tends to last for longer stretches later in the night. REM sleep is believed to provide essential support for neurological and memory functions. This is also the sleep stage when both dreaming and involuntary REM rapid eye movement – occur.

Do You Have Trouble Falling Asleep?

Nearly one in three adults has trouble with sleeplessness. If you’re struggling to sleep, try these six steps to a good night’s sleep, including sticking to a consistent sleep schedule, avoiding caffeine in the afternoon, walking, stretching and more. Get the full HEALTHY ESSENTIALS® list here.

Additionally, simple diet changes such as integrating complex carbs and opting for heart-healthy fats can help improve sleep cycles by boosting your body’s ability absorb tryptophan and increasing serotonin levels, both of which promote sleep. Learn more about diet and its impact on sleep here.

Another option? Consider SIMPLY SLEEP® Nighttime Sleep Aid, an over-the-counter medicine that is non-habit forming when used as directed. SIMPLY SLEEP® is for the relief of occasional sleeplessness.  

Links to third-party sources in this content are provided are for educational purposes only. No sponsorship or endorsement is implied. This article includes information from the National Sleep Foundation and the National Institutes of Health.

©Johnson & Johnson Consumer Inc. 2018

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