Sometimes, sleep is a lot more active than you think, but only under the surface. REM sleep is one of the sleep stages that you cycle through during the night, and while your body may be still, your mind resembles a waking state because of the vivid dreaming that occurs during REM sleep.
REM sleep is important for processing emotions and consolidating memories, but how can you be sure that you’re getting enough of it each night?
What is REM Sleep?
Throughout the night, you cycle through four stages of sleep, and REM sleep is just one of them.
Rapid eye movement (REM) sleep is one of two categories for these sleep stages; the other is non-rapid eye movement (NREM). Three of the night’s sleep stages qualify as NREM sleep, and they progress from just starting to fall asleep (N1), light sleep (N2), and then deep sleep (N3). Following this third stage, you enter REM sleep and then cycle back to the beginning.
REM sleep gets its name because the eyes move rapidly underneath closed eyelids, darting back and forth. However, while the eyes are active, the rest of the muscles in your body become temporarily paralyzed. This is important because REM sleep is when most of your vivid dreaming occurs—temporarily paralyzing the muscles helps to keep you from acting out your dreams.
Compared to NREM sleep, REM sleep involves more brain activity and is often considered a more “wakeful” state since heart rate and blood pressure increase to levels that are very similar to what is seen when you’re awake. On an EEG, the waves during REM sleep are theta waves, which are low-frequency waves that are also associated with being awake.
REM sleep is especially important for dreaming and emotional processing. However, memory consolidation also occurs during REM sleep, with the brain committing some things that you learned during the day to memory, maintaining those that continue to be important, and then deleting those that are no longer relevant.
There are a few sleep disorders that are associated with abnormal REM sleep. Nightmare disorder, for instance, occurs when someone regularly experiences intense nightmares, which usually occur during REM sleep. There’s also REM sleep behavior disorder (RBD), during which someone’s muscles do not become paralyzed during REM sleep, which results in them acting out their dreams or shouting. In many cases, RBD precedes the development of neurodegenerative diseases, and it’s suspected that RBD is caused by a deterioration of the brainstem area responsible for regulating REM sleep.
What Percentage of REM Sleep is Normal?
One sleep cycle takes between 90-120 minutes for adults, and REM sleep comprises about 25% of your sleep time—the other 75% is NREM sleep.
However, the amount of REM sleep that you get can vary by day; some days, you may get more REM sleep, and other days you may get less.
What Can Limit Your REM Sleep? (And Tips to Get More)
The greatest cap on how much REM sleep you’re able to get is how much time you spend asleep. If you go to bed late or find yourself waking multiple times during the night, you don’t spend enough time asleep, which can interfere with your REM sleep. Let’s explore both scenarios.
If you go to bed late and only have time for 6 hours of sleep, you may only get through four sleep cycles versus the 5 or 6 cycles that you could complete if you slept for a full 7-9 hours. With fewer sleep cycles, you spend less time in all stages of sleep, including REM sleep.
Another challenge is if you continually wake up during the night since each time you go back to sleep, you go back to the first sleep stage. Since REM sleep is the final stage, if you keep waking up during N2 or N3 sleep, you’ll go back to N1 and have to start all over again. When this occurs, you spend significantly more time in the NREM sleep stages than in REM sleep.
As for what may cause you to get too little REM sleep, these are some possibilities:
- Not setting aside enough time to sleep
- Having a sleep disorder (e.g., insomnia, restless legs syndrome, obstructive sleep apnea)
- Being stressed and unable to fall asleep
Given how important REM sleep is for your brain’s ability to consolidate and process information, your mood, and your mental concentration, you must maximize your time spent in this stage. Here are some tips to get more continuous sleep:
- Stay consistent. If you’re not giving yourself enough time to be asleep, you won’t be able to cycle through the sleep stages as often as your body needs. Additionally, if you’re irregular with your bedtimes, you may have a hard time falling asleep even if you go to bed early. To help your circadian rhythm, go to bed and wake up at the same time each day (and make sure these times leave 7-9 hours to sleep).
- Pause beverage intake. Waking up with a need to go to the bathroom is a common cause of nighttime disruptions, and you can help minimize this effect by limiting beverages an hour or two before bed. The less you drink, the less urine will build up, and the greater chance you can go through the night with minimal disruptions.
- Use a sound machine. Loud noises can rouse you from sleep, especially if you live in an urban setting where honking can continue long into the night. To help mask these sounds, consider using a sound machine that plays nature sounds or white noise. You could also try wearing earplugs to block out the noises, as well.
- Relax before bed. Stress and anxiety can make it hard to fall asleep, even if you give yourself enough time to sleep. Try relaxing activities before bed, such as meditation, to quiet your mind and place your body in the right state to drift off to sleep.
- Avoid electronics at night. Electronics give off blue light, which can suppress your production of melatonin and make it hard for you to fall asleep. Avoid electronics for at least an hour before bed so that your body can build up its melatonin production and ease the transition into the first stage of sleep.
If you find yourself waking up throughout the night and have also been told you snore, it may be worthwhile to schedule an appointment with your doctor to discuss the possibility of sleep apnea. This sleep disorder can cause numerous nighttime wakings, but there’s treatment available to help you sleep more soundly, which then offers more REM sleep.
When it comes to getting enough REM sleep, the key is to get enough sleep in general and to focus on limiting distractions that wake you up during the night. Once you sleep more soundly, you’ll give your body enough time to soak up REM sleep.
