REM sleep is the stage often associated with vivid dreams. Instead of chasing a perfect nightly number, focus on enough consistent sleep and how you feel during the day.
What happens during REM sleep?
Sleep alternates between three non-REM stages and REM. According to the National Heart, Lung, and Blood Institute, the first REM period usually begins around 90 minutes after falling asleep, and REM periods tend to become longer later in the night. The timing varies.
During REM, the eyes move rapidly, brain activity increases and breathing and heart rate become more variable. Most skeletal muscles are temporarily inhibited. Vivid dreaming is common during REM, though dreams can also occur in non-REM sleep. REM is involved in learning, memory and emotional processing, alongside other sleep stages.
How much REM sleep do you need?
Around a fifth to a quarter of adult sleep is a useful population-level approximation, not a diagnosis or a target everyone must hit. Newborns spend a greater proportion of sleep in REM, and sleep changes across the lifespan. If you sleep eight hours, 20–25% would be about 96–120 minutes; that example is arithmetic, not a personal prescription.
Because REM periods often lengthen toward morning, consistently cutting sleep short can reduce the opportunity to experience them. Protect the full sleep window rather than trying to manipulate one stage.
Habits that support healthy sleep
- Give sleep enough time. Most adults need about 7–9 hours, though individual needs vary. Keep a consistent wake time when practical.
- Make your bedroom comfortable. A dark, quiet and comfortably cool room can help reduce disruptions.
- Watch timing. Caffeine late in the day, alcohol near bedtime and irregular schedules can disrupt sleep for some people.
- Address persistent problems. If insomnia, loud snoring, gasping or frequent awakenings continue, ask a clinician about evaluation instead of relying on supplements or sleep-stage hacks.
Yawnder founder Ben Trapskin has described his own struggles with short, restless nights and the value of learning about sleep and improving routines. Your sleep needs and the reasons for disrupted sleep may be different.
Can a wearable measure REM accurately?
Most consumer wearables estimate stages from movement and signals such as heart rate; their numbers are not equivalent to the brain-wave measurements used in a clinical sleep study. A single low REM reading is not enough to diagnose a problem. Look for longer-term patterns and how rested you feel, and discuss persistent concerns with a professional.
When to seek help
Talk with a clinician if you regularly have unrefreshing sleep, significant daytime sleepiness, loud snoring or witnessed pauses in breathing. Seek assessment if you shout, punch, kick or otherwise act out dreams, particularly if anyone is injured. Do not change prescribed medicines to chase more REM without speaking with your prescriber.
Frequently asked questions
Is two hours of REM necessary every night?
No. Two hours is an illustration of what 25% of an eight-hour night would look like, not a universal requirement.
Can I get REM sleep during a nap?
It is possible, especially in longer naps, but timing varies. A nap is not a reliable substitute for sufficient nighttime sleep.
Do all dreams occur in REM?
No. Dreams can occur in other sleep stages, although REM dreams are often vivid.
Sources: NHLBI: Sleep stages; NHLBI: Get enough sleep. This guide is educational and does not replace medical advice.