Why Do I Always Wake Up After 5 hours of sleep?

Julia was at wit’s end. She has been suffering from insomnia for the past 10 years, since she entered menopause. She keeps waking up after 5 hours, despite trying every over-the-counter and prescription medication available. She has no trouble falling asleep, but is not able to stay asleep for more than 5 hours, typically waking up at 3AM after falling asleep at 10PM. Oftentimes, she has to go to the bathroom when she awakens, but it’s not too much urine. She even saw a behavioral sleep specialist who offered cognitive behavioral therapy for insomnia (CBT-i), which only helped temporarily. 
 
Julia’s history is typical for what’s called sleep maintenance insomnia, where you can’t stay asleep or keep waking up after you’re able to fall asleep. This differs from sleep onset insomnia, where you’re not able to fall asleep within 20 to 30 minutes of getting into bed. The accepted explanation for insomnia is that it’s a complex interaction between poor sleep routines, behavior and thoughts, in addition to a baseline hyperarousal of your brain. Essentially, you can’t shut down your brain when you want to go to sleep.
 
One of the potential consequences of sleep maintenance insomnia is that with continuous awakenings at AM and not being able to go back to sleep is that your sleep clock becomes advanced, or gets pushed backwards. This could potentially lead to advanced sleep phase syndrome, a condition that’s commonly seen in the elderly. In this condition, you’ll want to go to sleep much earlier in the evening, such as 8PM, rather than at 10PM.
 
I’ve always wondered why people tend to wake up around 3AM,  whether it’s insomnia, nighttime urination, or asthma. The most obvious connection between these three connections is that you spend longer periods of REM sleep (your dream stage), starting around 3AM. Stage REM is also when your muscles are most relaxed, which can predispose you to have breathing problems. I’ve been doing thought experiments about his concept, and I’m convinced that we need to think about sleep maintenance insomnia in a completely different way—perhaps it’s a consequence of a breathing problem.
 
Before I go over my arguments, a few basic sleep concepts need to be reviewed.
 
Sleep Position
 
If you see photos or drawing of people sleeping, you’ll often see sleep being depicted as someone sleeping on the back. However, most modern Western people prefer to sleep on their sides or stomach. One of many reasons is that supine (back) sleep will allow the soft tissues of the tongue and soft palate and fall back more due to gravity when supine.
 
Menopause
 
As women go through menopause, throat muscles will relax somewhat due to lowered progesterone levels. This study found that genioglossus muscle (tongue) activity is lower in post-menopausal women compared to pre-menopausal women. This is why women on hormone replacement therapy tend to sleep slightly better.
 
Your Circadian Rhythm 
 
Another major sleep concept that’s important to understand are two processes that are involved in sleep regulation. The first one is the well-known circadian rhythm. For many of us here on Earth, we are on a 24 hour cycle. The circadian rhythm, which is regulated by light, cycles up and down between two 12-hour intervals. This is called the C process. This is what makes you alert during the day and drowsy at night.
 
 
 
Your Drive for Sleep
 
There’s another simultaneous sleep-related phenomena called the S process. This is your drive for sleep, which is minimal in the morning when you first wake up, but then increases gradually reaching its peak before you fall asleep. Once you’re asleep, it drops back down to the baseline low level at which point you’ll wake up. 
 
Process S also corresponds to your level of adenosine that builds up in your brain. Adenosine inhibits wakefulness. As the day progresses, adenosine levels slowly increase. Ingesting caffeine from drinking coffee is one way that we block the effects of adenosine. 
 
The Importance of Sleep Stage 
 
Now there’s one more piece to the puzzle that’s critical. This is your sleep cycle. Normally, you’ll cycle between 4 defined stages of sleep: Wake, N1, N2, N3, REM. N1 and N2 are the lighter stages of sleep and N3 is deep sleep. During N1 through N3, your muscles become gradually more relaxed, but in REM sleep (rapid eye movement and dream stage),  your muscles are completely relaxed. 
 
 
 
You’ll reach deep sleep (N3) in the early part of the night, but as you progress through 4 to 5 sleep cycles (90 to 120 minutes long), N3 gets shorter and shorter and REM becomes longer and longer. Around 3 to 4 AM is when you begin to have longer periods of REM sleep. 
 
There are many different explanations on what causes us to wake up prematurely in the morning, but it’s probably a combination of  these three processes, along with sunlight that arrives in the morning. When you’re about to wake up, your circadian (wake forces) are beginning to increase from its lowest point, your sleep drive (S) is at its lowest point, and you’re most likely in REM sleep, when muscles are most relaxed, leading to possible obstructed breathing. This  can be a natural, normal waking mechanism. Notice that in many cases you’re waking up during a dream in the morning. Adding sunlight is another cue for you to wake up. 
 
In addition, the lowest point in the circadian cycle is called the singularity. It typically occurs around 2 hours before your natural wake up time. It’s also the time when your core body temperature is at its lowest. On the C&S figure, notice that this dip is about 2 hours before wake time. We also know that as core body temperature rises, you’re more likely to wake up. 
 
In the figure below, I’ve juxtaposed the hypnogram (sleep stages) underneath the C&S figure during 8 hours of sleep. 
 
 
 
All of the above is assuming that you have normal upper airway anatomy and you are able to wake up after sleeping 7 to 8 hours without any problems. However, if you have upper airway narrowing due to large tonsils or small jaws with dental crowding, you’re more likely to partially or totally stop breathing, whether it’s for 3 seconds or 25 seconds. Totally obstructed breathing for more than 10 seconds is called an apnea if detected during a sleep study. A breathing pause for less than 10 seconds won’t be counted as a formal respiratory event (apneas, hypopnea or RERA) but will most likely be counted as an arousal. 
 
We also know that obstructed breathing is more likely to occur during REM sleep, especially when you’re on your back. If you have more narrow upper airways, then the higher the likelihood of more frequent breathing pauses around 3-4 AM, when you’re in longer periods of REM sleep. If you add the various other factors mentioned above (circadian factors, sleep drive, sleep position, sleep stage, light, etc.), then you’re more likely to wake up around this time. 
 
Brain hyperarousal
 
One of the hallmarks of insomniacs is the inability shut down the brain when going to sleep, or after a nighttime arousal. It think you’ll agree with me that waking up due to choking and breathing pauses can be a major cause of physiologic, emotional and psychological stress.
 
Nighttime urination
 
Some of you may have to go to the bathroom to urinate. This is a common condition (nocturia) in people with obstructive sleep apnea or upper airway resistance syndrome due to a hormone (atrial natriuretic peptide) that’s created by your heart in response to stimulation from obstructed breathing, leading to more urine production. Some of you are able to go back to sleep, but some of you can’t fall back asleep. Whether or not you can fall back asleep may depend on how violently you woke up. If you just had a 30 second choking episode, this will lead to a major stress response, with heart rate blood pressure elevations. It’s unlikely you’ll be able to fall back asleep. 
 
Putting the pieces together
 
In medicine, and especially sleep medicine, we like to categorize medical conditions into separate categories. It assumes that obstructive sleep apnea is completely different from insomnia. However, when it comes to these two conditions, there is compelling evidence that there can be a great deal of overlap when it comes to presenting symptoms. 
 
One example of this overlapping phenomenon is a study performed by Dr. Barry Krakow. He and his colleague reviewed 218 patients with prescription medication resistant insomnia, and 75% were found to have obstructive sleep apnea based on formal sleep studies.
 
Julia eventually made her way to find me and not surprisingly, she was found to have moderately obstructive sleep apnea (AHI 20).  She began using CPAP, and finally able to sleep for 7 hours again like she used to when she was in her teens. Looking back on her history, she suffered a shoulder about 8 years ago. This forced her to sleep on her back, when she normally preferred to sleep on her side. She began to gain weight later, and began to snore heavily. 
 
This alternative explanation for sleep maintenance insomnia may seem a bit fat fetched for traditional sleep scientists, but looking at this from a sleep-breathing standpoint, it makes a lot of sense. How many of you keep waking up much earlier than your preferred time? What have to tried so far? Please enter your responses in the text box below.
 
 
 
 
 
 
 
 
 
 

Please note: I reserve the right to delete comments that are offensive or off-topic.

Leave a Reply

Your email address will not be published. Required fields are marked *

9 thoughts on “Why Do I Always Wake Up After 5 hours of sleep?

  1. Dear Dr. Steven Park:
    Is it true that some expert said CPAP could not lengthen the time of sleep but just improve the efficiency of sleep?
    What can we do if we want to increase the sleep cycles from 3 to 4?

  2. Around 1996 I was diagnosed with a thyroglossal duct cyst and underwent a procedure to remove the hyoid bone. My health and weight was excellent. Over the years I gradually gained weight and began snoring. Currently my weight is about 228 lbs at 5’10”. For several years my sleep patterns had been very poor. Often waking up several times in the night. Sometimes being excessively tired during the day. My children complained of my snoring and my wife was concerned that by my pause in breathing during my sleep. Finally at her insistence I saw a doctor who prescribed a sleep study. I was quickly diagnosed with sleep apnea. I now reluctantly use a CPAP machine. I have been using the machine for about 6 weeks. I must admit my sleep is better and I feel more rested. That said I still wake up after 4 to 5 hours. Then go back to sleep about an hour later. I believe the combination of my thyroglossal duct cyst surgery and weight gain has contributed to my sleep apnea. I was unaware that my waking up after 4 to 5 hours even when using a CPAP device may still be related to my breathing. I always suspected but didn’t know that my prior survey could also contribute. Thank you for your website information. I would be interested in learning if there are options available to correct prior thyroglossal duct cyst surgery that are worth the risk.

  3. Mr. Cox,

    Thanks for sharing. I’ve always suspected that thyroglossal duct cyst surgery may worsen sleep quality by relaxing the tongue and epiglottic structures. Poor sleep then will aggravate weight gain, and the vicious cycle continues.

    Unfortunately, there’s no formal way of reversing your surgery, except for the standard surgical treatment options for obstructive sleep apnea. It’s not something that most ENTs and sleep doctors may acknowledge. Your best bet is to better optimize your current CPAP treatment. Good luck.

  4. Zing,

    I have seen many people lengthen their sleep time significantly on CPAP, with more uninterrupted sleep cycles.

  5. I’ve probably been waking up between 3 and 4 for much of my life, but the problem has become more acute in the past year, leading to considerable fatigue (but no more sleep). I start out sleeping on my side, but I usually have flipped on my back before I wake up. Sometimes, I feel like I’m holding my breath when I wake up. I’ve had sleep studies in 2004 and 2016, but neither showed any breathing problems. In the past few months, I’ve learned about how many sleep studies will not detect UARS. I’ve also discovered, through working with dental and orofacial providers, that I a) breath through my mouth when I sleep, leaning to morning dry mouth; b) had a tongue tie (until I had a frenectomy last month; and c) had TMJ and a rethrognatic jaw. I’ve had some success with mouth taping/breathe-rite strips, the frenectomy, and a Farrar mandibular advancement device, but sleep is still too short and unrefreshing (although my dreams seem to run longer, suggesting that R.E.M. is getting better). I have an appointment on Thursday with a sleep doctor who trained at Stanford and has published popular and scholarly articles about UARS (Dr. Gerald Meskill). I am hoping for a diagnosis (since it’s kind of weird going around saying that you think that you have an undiagnosed sleep disorder) and some ideas for the path ahead.

  6. Dr. Park,
    This is me every night, sometimes less than 5 hours perhaps 3-4 hours. I have moderate OSA and I’ve been using a SomnoMed oral appliance (used to have CPAP but sleep doctor encouraged me to use an oral appliance because of my orofacial structure).
    I still feel tired daily – I try to compensate for wake ups by sleeping longer but seems to have no effect. I would love to have 7+ hours of uninterrupted sleep.
    Also, I remember a lot of my dreams so I’m getting into my REM sleep but I find it strange since my sleep is slightly interrupted – my AHI is between 4-6.5 (95% hypopneas, 5% apneas), maybe its my few apneas that is throwing it all off – I get that one big apnea and I’m awake?. My dentist suggests doing another sleep study to determine if i should move my lower jaw forward. Probably just to confirm the previous study. I would really prefer to stick with the oral appliance than go back to CPAP but feeling tired all the time is causing me to consider CPAP again, maybe just to compare.
    Do you know of patients that alternate between CPAP and oral appliance or is it best to stick to just one? My Somno is ideal choice but I’m trying to be realistic and want to keep moving in a positive direction towards uninterrupted sleep – this is my biggest goal in my life.
    Not sure why my dentist is being so cautious since my SomnoMed is not that far ahead either.

  7. I have had trouble falling asleep since I was a child, however in the past 8 year it’s become progressive harder to fall asleep and we I do fall asleep harder to actually stay asleep. I toss and turn, I can’t sleep on my back (I sue to be able to) and I wake up many times to urinate. I’m fatigue most of the morning then about 7pm I get a surge of energy and struggle to want to go to bed.

    I’m a 33yo female mother of 2yo toddler, I’m not over weight and I don’t smoke. This chronic sleep deprivation is killing me. I work fulltime and I struggle so much to get out of bed in the morning I feel fatigued for hours after awaking up and I find myself feeling depressed and angry. It’s effecting my relationship with my husband and intimately too.

    My sleep study results are high level of hypopnea incidents but no sleep apnea.

    My ENT says there everything looks normal but recommended Pillar Implants as perhaps my soft palate is blocking my airways.

    I think that’s possible but I also this something is going on in my nose, it feels stuffy in the morning. I think when I sleep it’s through my mouth not my nose.

    I wish there was a Dr like you here in Sydney Australia!!
    When you write about the effects of UARS is resonates so much with me it’s like you writing about me and what I’ve been dealing with all these years :(

  8. I’m 62 and my sleep situation in post menopause is similar to “Julia” in your example. Over 5 yrs ago my sleep patterns were steadily transitional from daytime sleepiness after what I thought was a normal 7 hrs of sleep to chronic insomnia wit waking up for no apparent reason and eventually unable to return to sleep after abruptly waking up at 2-3:00am. Years of suffering with sleep deprivation and undergoing Extensive medical tests for other disorders like numbness, ibs, gastritis, afib, urithitis, insulin resistance, restless legs, and more, which I believe were all caused by sleep apnea. Finally after yrs of seeing drs off and on, an NP in a neurology clinic listened to me describe my fragmented and vivid dreams right before waking in early morning. Even though I’m not overweight and don’t have high blood pressure she referred me for a sleep study. I got my slap machine which helps give me more continuous sleep off and on and I get about 5-6 hrs sleep with 0.25 my of clonazepam which I’ve been taking for 2.5 yrs. Would like to wean off that drug so just lately I’ve decided to try OTC bioidentical progesterone Cream. I see it helps some older women sleep better. Hoping it will help improve my sleep breathing, improving airway and tongue muscle. I also have a small jaw, have narrow airway, most likely made worse by extensive tooth extractions and headgear orthodontics in my late teens, early 1970’s.

    Than you for all your research and internet articles and podcasts on sleep breathing disorder and sleep apnea.

  9. Hi Im also experiencing the same issues like julia.. I dont have trouble falling asleep, but i woke up every 4-5 hrs just to pee and after that i cant sleep anymore. Hoping for some answers.. Tnx