Imagine spending eight hours in bed and waking up more exhausted than when you went to sleep. You’re getting plenty of time under the covers, but somehow your body never gets the rest it desperately needs. For millions of Americans, this isn’t just an occasional bad night—it’s a nightly battle with a condition called sleep apnea, where breathing repeatedly stops and starts throughout the night.
Sleep apnea causes repeated interruptions in breathing during sleep, and it’s far more common than most people realize. Over 936 million adults worldwide aged 30-69 have some form of sleep apnea, though many don’t know they have it. The challenge is that the most dramatic symptoms happen while you’re unconscious, making it a disorder that often requires someone else to notice before you realize there’s a problem.
What Actually Happens During Sleep Apnea
The most common form is obstructive sleep apnea, which accounts for the vast majority of cases. During obstructive sleep apnea, the muscles in the back of the throat relax too much, causing the upper airway to collapse and interrupt breathing. Think of it like trying to breathe through a straw that keeps getting pinched shut—your body is trying to get air, but the pathway keeps getting blocked.
Each pause in breathing, called an apneic event, lasts at least 10 seconds and can occur dozens or even hundreds of times per night. When oxygen levels drop, your brain essentially sounds an alarm, triggering a brief arousal to restart breathing. These micro-awakenings fragment your sleep into tiny pieces, preventing you from getting the deep, restorative rest your body needs. The termination of each apneic event is associated with a transient arousal from sleep, but these don’t register in your conscious memory. You don’t wake up in the morning thinking “I woke up 247 times last night.” Instead, you just feel terrible despite thinking you slept through the night.
There’s also central sleep apnea, which works differently. With central sleep apnea, the brain fails to send proper signals to the breathing muscles during sleep. Instead of a physical blockage, it’s a communication breakdown between your brain and the muscles that control breathing. Some people even have complex sleep apnea, which combines both types.
How Sleep Apnea Gets Diagnosed
Doctors measure the severity of sleep apnea using the apnea-hypopnea index, which counts the average number of breathing pauses per hour. An AHI between 5 and 14 events per hour is considered mild, 15 to 29 is moderate, and 30 or more is severe. Someone with severe sleep apnea might stop breathing more times in a single night than they’d care to count.
The gold standard for diagnosis is polysomnography—an overnight sleep study conducted in a specialized lab. During polysomnography, doctors monitor brain waves through an electroencephalogram, track oxygen levels with pulse oximetry, measure airflow through temperature and pressure sensors, and use respiratory belts to monitor chest and abdomen movement. It’s like turning your body into a living data collection system for one night, with sensors measuring everything from your heart rate to how your legs move during different sleep stages.
For many people, though, home sleep testing is a more convenient option. Home sleep apnea tests use a limited subset of measurements—typically heart rate, oxygen levels, respiratory effort, body position, and nasal airflow. While these portable devices can’t capture everything a full lab study can, they’re often sufficient for diagnosis and much easier to arrange.
Treatment Options: From Lifestyle Changes to High-Tech Solutions
The most effective treatment for moderate to severe sleep apnea is continuous positive airway pressure therapy, better known as CPAP. CPAP works by delivering air through a mask to keep airways open during sleep. Think of it as a gentle wind tunnel that prevents your throat from collapsing. The device maintains constant air pressure, essentially splinting your airway open so you can breathe normally throughout the night.
But here’s the challenge: nearly half of patients don’t consistently use CPAP after the first month. The mask can be uncomfortable, some people find the pressure sensation strange, and it takes getting used to sleeping with equipment on your face. For people who can’t tolerate CPAP or have milder cases, there are alternatives like oral appliances that reposition the jaw and tongue to keep the airway open.
Surgery is another option, though it’s typically reserved for specific situations. Surgical options include procedures to remove enlarged tonsils or adenoids, or to address abnormalities causing airway obstruction. There’s even a newer treatment called hypoglossal nerve stimulation, which uses an implanted device to stimulate the nerve controlling tongue movement, keeping it from blocking the airway.
For some people, lifestyle modifications can make a real difference, especially with mild cases. Weight loss often helps since obesity is a major risk factor for sleep apnea. Sleeping on your side instead of your back can reduce airway collapse, and avoiding alcohol before bed helps because alcohol relaxes throat muscles even more.
Sleep Apnea Versus Insomnia: Two Very Different Beasts
Here’s where things get interesting—and sometimes confusing. Sleep apnea and insomnia are fundamentally different disorders, yet they can look similar and even occur together. Sleep apnea is primarily a problem of abnormal breathing during sleep, while insomnia is an inability to fall asleep or stay asleep.
With insomnia, your brain is often the problem—it won’t shut off when you want it to. You lie awake with racing thoughts, or you fall asleep only to pop awake an hour later, mind already churning. People with insomnia are usually very aware that they’re having sleeping difficulties. They know exactly how long they’ve been staring at the ceiling.
Sleep apnea operates differently. Many people with sleep apnea don’t realize they have breathing problems during sleep, as the awakenings are so brief they’re not consciously aware of them. You might spend what feels like a full night asleep yet wake up exhausted. Your problem isn’t falling or staying asleep in the traditional sense, it’s that the sleep you’re getting is constantly interrupted and of terrible quality.
The plot twist is that these conditions can feed into each other. Sleep apnea causes numerous micro-awakenings that disrupt sleep and can lead to insomnia-like symptoms. When you’re waking up dozens or hundreds of times per night, even if you don’t fully remember it, your sleep architecture gets shredded. This fragmentation can trigger the hyperarousal and sleep anxiety characteristic of insomnia.
Between 30-50% of people with sleep apnea also experience chronic insomnia symptoms, a combination researchers call COMISA (comorbid insomnia and sleep apnea). This overlap creates treatment challenges because patients with both conditions may have difficulty tolerating CPAP due to frequent awakenings and an inability to fall back asleep with the mask in place.
How Would You Know If You Have Sleep Apnea?
This is the tricky part—you’re unconscious when it happens. Loud snoring, snorting, or gasping during sleep is a major warning sign, though not everyone who snores has sleep apnea and not everyone with sleep apnea snores. If you live alone, you might never hear these sounds yourself.
Often, it’s a bed partner who first notices something’s wrong. They might observe you stop breathing, then suddenly gasp or snort as you restart. People with sleep apnea often toss and turn and show signs of restless nighttime sleep, sometimes waking up with sheets twisted and pillows scattered.
The daytime symptoms are easier to recognize. Waking with a headache, not feeling refreshed despite adequate time in bed, and feeling tired throughout the day, even to the point of dozing off, can all signal sleep apnea. If you find yourself nodding off while reading, watching TV, or worst of all, driving, that’s a red flag. For many people, the only obvious symptom of sleep apnea is fatigue or excessive sleepiness during the day.
Other clues include waking up with a very dry mouth or sore throat (from breathing with your mouth open all night), frequent nighttime urination (sleep apnea can affect bladder sensation), difficulty concentrating, or mood changes. Some people even experience sexual dysfunction or decreased interest in sex due to the chronic sleep deprivation.
.The research suggests that some people may develop a heightened awareness over time, particularly if they also develop insomnia symptoms. Some patients with comorbid insomnia and sleep apnea may associate post-respiratory event awakenings with wakefulness, resulting in prolonged difficulty falling back asleep. In these cases, what started as unconscious micro-arousals can evolve into conscious awareness and anxiety about sleep disruption.
Why This All Matters
The health consequences of untreated sleep apnea extend far beyond feeling tired. Sleep apnea increases the risk of high blood pressure, irregular heart rhythms like atrial fibrillation, heart disease, and stroke. Each time your oxygen levels drop during a breathing pause, it stresses your cardiovascular system. Over months and years, this repeated stress can lead to serious complications.
There’s also the immediate danger of extreme daytime sleepiness. Excessive daytime sleepiness can cause microsleeps where you fall asleep for very brief periods—dangerous while driving or operating machinery. The cognitive fog, mood disturbances, and reduced productivity affect quality of life even if you never have a serious accident.
The good news is that treatment works. With proper diagnosis and appropriate therapy—whether that’s CPAP, an oral appliance, surgery, or lifestyle changes—most people see dramatic improvements in their sleep quality and daytime functioning. The key is recognizing the problem in the first place, which requires paying attention to those subtle clues your body provides during the day about what’s happening at night.
Medical Disclaimer
The information provided in this article is intended for general educational and informational purposes only and does not constitute medical advice. It should not be used as a substitute for professional medical advice, diagnosis, or treatment.
Always seek the guidance of a qualified healthcare provider with any questions you may have regarding a medical condition or treatment. Never disregard professional medical advice or delay seeking it because of something you have read here.
If you are experiencing a medical emergency, call 911 or your local emergency number immediately.
The author of this article is a licensed physician, but the views expressed here are solely those of the author and do not represent the official position of any hospital, health system, or medical organization with which the author may be affiliated.
Image generated by author using ChatGPT
Sources:
Mayo Clinic – Sleep Apnea: Symptoms and Causes
https://www.mayoclinic.org/diseases-conditions/sleep-apnea/symptoms-causes/syc-20377631
Cleveland Clinic – Sleep Apnea: What It Is, Causes, Symptoms & Treatment
https://my.clevelandclinic.org/health/diseases/8718-sleep-apnea
Merck Manual (Professional Edition) – Obstructive Sleep Apnea (OSA)
https://www.merckmanuals.com/professional/pulmonary-disorders/sleep-apnea/obstructive-sleep-apnea-osa
StatPearls/NCBI – Obstructive Sleep Apnea
https://www.ncbi.nlm.nih.gov/books/NBK459252/
American Lung Association – Obstructive Sleep Apnea Symptoms and Diagnosis
https://www.lung.org/lung-health-diseases/lung-disease-lookup/sleep-apnea/symptoms-diagnosis
To Sleep, Perchance to Dream -Wm. Shakespeare, Hamlet
By John Turley
On September 2, 2023
In Commentary, Medicine
Sleep – Part I
The other night, about 3:00 AM I was lying in bed wide awake thinking about…. sleep. It’s natural to think about sleep when you’re having trouble doing it. I’ve had intermittent insomnia for my entire adult life. Sometimes I’ll go several days with not much more than two or three hours of sleep a night and then I’ll go several days where I can sleep six, seven or eight hours. I’m not sure what causes insomnia at one time but not another.
I’ve spent a lot of time thinking about sleep. Mostly, I think about why I can’t sleep and what I can do to get to sleep. I’ve read a lot about specific tips and techniques to improve sleep. I’ve tried many of the so-called “sleep hygiene” regimens. I’ve tried herbal preparations and prescription sleep medications. Lately I’ve been using a sleep mask with some positive results. I’m easily awakened, and it has helped with that.
But, with one of those middle of the night revelations, I realized that in all my years of thinking about sleep I’ve never really thought about what sleep is and why we need to do it. So, I’m going to embark on a three-part post about sleep. This is Part 1; it’s a look at what sleep is and why we do it. In Part 2 we’ll look at why we can’t sleep and the various things that cause us to lose sleep. Part 3 will be a survey of the many things available that may or may not help us to get that good night’s sleep.
What Is Sleep?
We will spend anywhere from 25 to 30% of our lives asleep so we really ought to have a better understanding of exactly what it is.
Merriam-Webster defines sleep as: The natural, easily reversible periodic state of many living things that is marked by the absence of wakefulness and by the loss of consciousness of one’s surroundings, is accompanied by a typical body posture (such as lying down with the eyes closed), the occurrence of dreaming, and changes in brain activity and physiological functioning….
As with many dictionary definitions my first response is “What?” So, let’s see if I can come up with something that’s a little more than a physical description of someone laying on the couch asleep.
Our bodies crave sleep just like they crave food. The major difference is your body can’t force you to eat but it can force you to sleep.
The reasons why we sleep and what happens during sleep are not completely understood. People used to believe that sleep was a passive activity when the brain and the body were dormant. But, according to sleep specialist and neurologist Dr. Mark Wu, MD “… it turns out that sleep is a period during which the brain is engaged in a number of activities necessary to life which are closely linked to the quality of life.”
Cycle of Sleep
Everyone’s heard of the sleep cycle so I’m just going to briefly touch on it here. There are two basic types of sleep. The first is non-REM sleep which also has three stages of its own and the second is the rapid eye movement (REM) sleep.
The three stages of non-REM are Stage 1 which is the transition into sleep and is relatively light. It is when brain waves begin to slow down. Stage 2 is the period just before you enter into deeper sleep when your heart rate and breathing slow, your muscles relax, your body temperature starts to drop, and eye movements stop. This is the stage where you spend most of your sleeping time. Stage 3 of non-REM sleep is the period of deep sleep that you need to feel refreshed in the morning. It occurs more during the first half of the night. Your heartbeat and breathing are slowed to their lowest level, and you are most relaxed. Brain waves are at their slowest.
REM sleep first occurs about 90 minutes after falling asleep. Your eyes move rapidly even though your eyelids are closed. Your brain waves are closer to those when you are awake. Breathing becomes faster and your heart rate and blood pressure increase. This is when most of your dreaming occurs. Although, some can occur during non-REM sleep periods. During REM sleep your arm and leg muscles may become temporarily paralyzed which prevents you from acting out your dreams. As you age, you spend less time in REM sleep.
What Happens When We Sleep?
If we’re going to spend this much time sleeping there must be some benefit to it, right? Surely it is not just a way to pass the time until we have something better to do.
There have been a lot of theories over the years about why we sleep. Some of the older ones include the adaptive or evolutionary theory that says animals sleep during periods of vulnerability, such as darkness, so that they won’t attract attention. However, this seems to be counterintuitive. During periods of vulnerability, I would certainly want to be most alert. Another theory is that of energy conservation. During periods of sleep the body has less need for energy and will not require food as often. For most of human history, and continually for the rest of the animal world, food is a scarce item and energy conservation is important to survival.
People have always recognized that somehow sleep helped rejuvenate us. Newer research points to this as probably the main reason why we sleep. Sleep helps clear the brain of waste products that accumulate when we are awake allowing it to function more efficiently.
Sleep also helps us consolidate the day’s memories. It facilitates the conversion of short term to long term memories so that they are more readily accessible. Sleep also improves alertness, concentration, and cognitive performance. This may be why some people recommend a good night’s sleep rather than an all-night cramming session prior to finals.
Sleep helps regulate various hormones that are responsible for appetite control, growth, and metabolism. Poor sleep can exacerbate physical problems such as diabetes, hypertension, and obesity. Sleep is essential to our immune function; prolonged periods of sleep deprivation put us at risk for opportunistic infections. Sleep is also important for our emotional well-being and for helping to prevent anxiety and depression.
I will finish this post with two quotes that I particularly like about why we sleep.
Sleep is an investment in the energy you need to be effective tomorrow.
-Tom Rath, American author and consultant
Sleep is the golden chain that ties health and our bodies together.
-Thomas Dekker, 17th Century English poet and playwright