Upper Airway Resistance Syndrome

Note: This is an edited transcription of a podcast recording 

Today, we are going to spend the next 30 minutes talking about upper airway resistance syndrome, or UARS. It’s a relatively new description of a condition that’s related to obstructive sleep apnea but as you’ll hear in this podcast, has enormous ramifications in regards to so many health conditions that we see, not only in our field, but in almost every other field in general. I have to say, however, that this is a condition that is not yet accepted by the medical community as it is a relatively new diagnosis and much of what I will talk about is based on my own experiences in my practice. If you think you may have this condition, please see your doctor first and get a complete medical evaluation before considering this diagnosis. In my practice, I am amazed at how consistently I see the same pattern over and over again and I am excited to share this new information with you. 

Introducing UARS

Upper airway resistance syndrome was first described by researchers at Stanford University in 1993. They described a group of young women and men who complained of chronic fatigue and excessive daytime sleepiness. They all also underwent a formal sleep study and all were found not to meet the official criteria for obstructive sleep apnea. However, by treating them as if they had obstructive sleep apnea, most improved significantly. To understand how upper airway resistance syndrome is unique or different from sleep apnea, you have to first understand what obstructive sleep apnea is.   

Obstructive sleep apnea is a well-known sleep related breathing disorder characterized by repetitive breathing cessations during sleep, due to total collapses of the tissues of the throat.  This can happen anywhere from a few times every hour to over 100 times every hour. By definition then, apnea is defined as a total cessation of breathing for 10 seconds or more. And hypopnea is restricted breathing with greater than 30% chest wall movement decrease and blood oxygen drop of more than 4% for 10 seconds or more. A pretty complicated definition! The total combinations of apneas and hypopneas for the entire night divided by the total number of hours one sleeps gives us the apnea/hypopnea index or the AHI. This is the most commonly used measure to diagnose sleep apnea. Untreated, sleep apnea can lead to hypertension, diabetes, obesity, depression, lack of sexual desire, heart disease, heart attack or even stroke.   

How UARS Differs From Obstructive Sleep Apnea

Unlike sleep apnea where you have obstruction, apnea, then arousal, UARS patients typically have mostly obstructions and then arousals. As mentioned previously, all UARS patients have some form of fatigue, almost all state that they are “light sleepers,” and almost invariably, they don’t like to sleep on their backs. In some cases, they actually can’t. Some people attribute their poor quality sleep to insomnia, stress or working too much. Due to repetitive arousals at night, especially during the deeper levels of sleep, one is unable to get the required deep, restorative sleep that one needs to feel refreshed in the morning. In most cases, the anatomic reason for this collapse is the tongue. There are many reasons for the tongue to cause obstruction including being too large or being overweight. But once it occurs, the only thing you can do is to wake up.   

In deeper levels of sleep, especially during REM sleep, the normal protective layers of muscle tone that keeps your airway open during inspiration diminishes. So, if your airway is normal to begin with and you take a deep breath in, a vacuum-like pressure is set up and the back of your tongue can fall back completely. In many cases, whenever I examined this narrowed airway with the patient lying flat on his or her back, all I see is a 1-2mm slit between the back of the tongue and the throat.   

When awake, you’re fine, but once you start to fall asleep, the tongue falls back and you wake up, either fully or subconsciously. This is why so many people can’t fall asleep on their backs and therefore, have unconsciously trained themselves to roll over to their side or their stomach where the tongue collapse is less likely, although it can still happen. This can happen 10, 20 or 30 times every hour preventing you from sustaining deep sleep. You may realize that you are waking up sometimes, but the vast majority of arousals are subconscious. If this happens for a few nights in a row and you return to your normal sleep habits, you’re fine. But if it occurs continuously for months or years, then certain events can happen. 

Due to repetitive arousals, your body goes into almost a chronic state of low-grade stress. Think of what would happen if somebody poked you with their finger every few minutes while you tried to sleep for 6 months straight. Think about how you would feel the next morning. Think about how you would feel after months or years of inefficient sleep. You would feel tired, groggy with no motivation to do anything, have focus or concentration problems, or, you could feel depressed.   

How UARS Affects Your Autonomic Nervous System (ANS)

Physiologically, these multiple arousals also affect what is called the autonomic nervous system, or the ANS. The ANS is the internal nervous system that regulates your internal body functions such as digestion, breathing, heart rate, blood pressure, etc. It’s divided into two parts: the sympathetic and the parasympathetic parts. When you’re frightened or running away from a bull, your heart rate and blood pressure goes up, your vision and hearing are very sensitive, and all your blood flow and energy are mobilized around a fight. These functions are activated by the sympathetic nervous system. In contrast, after a good meal, your digestive organs kick in and begin to break down your food and you feel sleepy. This is your parasympathetic nervous system working.   

Your autonomic nervous system is in a constant state of relative balance between the two, depending on what you’re doing. Imagine if you’re stressed because you keep waking up at night for years. Your sympathetic nervous system becomes overly activated and stays active even when awake. A number of events can occur. Your hands or feet can become cold or numb, in general, activated by cold temperatures or stress. Some people have to wear mittens or socks all year round. This condition is called Raynaud’s phenomenon. There are many theories as to why people why so many people have this condition but there is no definitive cure. Since you’re under stress, your body thinks that it is under attack and it shunts blood from your peripheries to the more central muscles and to the heart, so that you can run or fight more effectively.  This might actually validate the saying “cold hands, warm heart.”   

How UARS Affects Your Gut

Similarly, since you don’t need to digest food when you’re fighting, blood gets shunted away from your entire gastrointestinal system to the heart muscles, leading to chronic diarrhea, constipation, indigestion, acid reflux or bloating. Remember the last time you were stressed?  How well were you able to eat, or digest food if you had just eaten? We already know that stress can aggravate acid production in the stomach. In addition to chronic gastrointestinal problems, many people with UARS also have LPRD, or laryngopharyngeal (throat and voice box) reflux.  It’s somewhat different than GERD, or gastroesophageal reflux disease. In most cases, you won’t feel any heartburn or the classic symptoms associated with GERD.   

The common complaints of LPRD include one or many of the following:  chronic throat clearing, postnasal drip, hoarseness, cough, throat or ear pain, lump in the throat, difficulty swallowing, tightness or pain with swallowing. You don’t have to feel any heartburn, either. Studies have shown that once acid reaches the throat, it can also go into the lungs, causing or aggravating asthma or bronchitis and even into the nose and ears causing more aggravating nasal congestion, sinus or ear infections.   

Pepsin, one of the stomach’s digestive enzymes and even H. pylori, a bacteria that can cause stomach infections have been found in the lungs, ears and the nasal cavity in people with infections. Any degree of swelling or irritation blocking the very narrow ear or sinus openings can cause pressure build-up or infections.   

How UARS Leads to Low Blood Pressure

Another study showed that in about 23% of people with UARS have low-blood pressure, sometimes dangerously low. In addition, these people frequently are dizzy or lightheaded, aggravated by standing up too soon. This is called orthostatic intolerance.  Even if the blood pressure is normal, one may still be prone to episodes of dizziness or lightheadedness.   

Recurring periods of stress may confuse your autonomic nervous system, so it doesn’t respond to the changes in blood flow and head position appropriately or quickly enough. People can also have chronic or recurrent sinus pain or pressure or infections, which can be debilitating.  Frequently, patients are  seen multiple times for recurrent sinus infections, given antibiotics (which only help temporarily), and in many cases, migraines can also masquerade as a sinus headache without the classic symptoms. 

Your nose is also regulated by the two opposing parts of the autonomic nervous system.  Studies have shown that there is an imbalance between the two parts of the ANS in the nose in people with acid reflux or sleep apnea. Thus, many people with either sleep apnea or UARS have chronic runny or stuffy noses with postnasal drip and are prone to sinus headaches or infections.  This process, in addition to the acid exposure described earlier is a very good reason for chronic nasal or sinus problems.   

The Link to Headaches, TMJ and Depression

Classic migraine and tension headaches are also frequent in UARS along with TMJ (temporo-mandibular joint) problems, due to grinding and clenching of the teeth. Sometimes these sinus headaches and pressure problems responded to decongestants and sometimes, anti-migraine medications. One doesn’t have to have the classic, typical migraine headache to have one. A recent study showed that in most cases of self-diagnosed sinus headaches, they were actually migraines.  Regardless of what comes first, the chicken or the egg, one probably aggravates the other, leading to a vicious circle.  TMJ can also give you ear pain, headaches along the side of your head, and it can also wear down your teeth.   

UARS is also associated with depression, anxiety or attention deficit problems. For obvious reasons, sleep deprivation, especially deep sleep deprivation with multiple arousals, can lead to many of these conditions. In addition, if you don’t sleep deeply, it’s been shown that your body produces increased levels of cortisol. And as we all know, cortisol is what makes you gain weight and eat more. It also lowers your immune system’s ability to fight infections and aggravate insulin resistance, leading to diabetes.   

Why Sleep Position is Important

Almost invariably, people with UARS prefer not to sleep on their backs. Many people state that if they try, they choke or wake up as they fall asleep. Over the years, they have trained themselves to sleep on their side or their stomach. Even then, they obstruct and wake up to a certain degree.  Many people also state that they have crazy or vivid dreams or sometimes no dreams at all. This is because when you wake up while you’re dreaming in REM sleep; you’ve remembered your dreams vividly. By definition, all dreams are wild and vivid. Only because you tend to wake up more frequently when you are dreaming, do you remember your dreams more vividly. Some people wake up as they begin to enter the dreaming stage, so they never dream at all.   

Family history is also very important. This is one way that I gauge what the patient might look like in 20-40 years. And in many cases, patients with UARS or sleep apnea have one or more parents that snore severely with one or many of the cardiovascular consequences such as obesity, diabetes, high blood pressure or heart disease. If one parent is noted to have had a heart attack or stroke in their 40’s or 50’s, I take the patient’s condition more seriously.   

Natural History of UARS

The natural course of UARS is highly variable with some patients remaining unchanged for years or decades, where others are slowly progressing into sleep apnea. Some older, overweight women in their 50’s or 60’s with sleep apnea tell me that when they were in their 20’s, they were very thin and had cold hands, low blood pressure, chronic diarrhea, and dizziness, and now they don’t have any of these conditions except that now they have high blood pressure, snoring and severe fatigue.   

What seems to aggravated UARS symptoms most however, is a relative change in their lives.  So a relative weight gain, even 5 or 10 pounds, can aggravate the symptoms which go away once the weight has stabilized and as the body adjusts and accommodates to the new weight. A bad cold or infection can also aggravate these symptoms, since it causes swelling, which narrows the upper airway. Pregnancy is another situation where this occurs. 

UARS people who are already living on the edge tend to have more prolonged or severe colds as airway swelling causes more narrowing and anatomic collapse, which further aggravates throat acid reflux, which causes more swelling, perpetuating the vicious cycle. At a certain point, the body can’t adjust and the vicious cycle is self-perpetuating. Poor sleep can also aggravate weight gain for reasons described before, previously. Weight gain narrows the throat even more, causing more obstruction and arousals.  Stress is also a big factor, whether it is emotional, psychological or physical. Whether the stress is internal or external, the body behaves the same way. 

My Wife’s Experience

On a personal note, my wife has many features of UARS. She has cold hands and low blood pressure. But after each of her two pregnancies, her UARS symptoms were greatly exaggerated.  After our first son, she had severe postpartum depression for almost a year. Only after she lost her entire pregnancy weight did she feel back to normal. After our second son was born, for four months she was severely lightheaded and dizzy, to the point of not being able to function properly. She saw a number of doctors and even had to go to the Emergency Room because one doctor thought she was having a stroke. The only objective finding was that her low blood pressure, which was low to begin with, was even lower. Only after she lost her entire pregnancy weight, did this condition go away. Sure enough, when I looked at her airway lying down, she had the typical narrowed airway behind the tongue.  Furthermore, her father has known moderate sleep apnea with diabetes. 

How To Diagnose UARS

So how does one diagnose UARS?  The first step is to undergo a complete ear, nose and throat evaluation. In most cases, the exam is normal. Sometimes what we’ll see is a deviated septum or nasal congestion due to allergies but more commonly what you’ll see is when we look in the mouth, the back of the throat is very narrow and you’ll have a very large tongue that sits very high up, covering up the uvula, the little thing that hangs down in the middle of your throat.   

The next step is to undergo an endoscopic evaluation, meaning that a small, tiny camera is placed through your nose and your airway is visualized. Normally, when you look at the airway, you can see the vocal cords behind your voice box but in people with UARS, the tongue fits further back, so most of the voice box is covered up. Especially if the person lies down, the tongue falls back even more, leaving a 1-2mm slit. When you are awake, you can breathe through this slit.  But as you fall asleep, the muscles relax as you get deeper into sleep. Then, when you reach deeper levels of sleep, or REM sleep (when you’re dreaming), the muscles have to relax completely and that’s when you start to obstruct. Then, once you obstruct, you stop breathing and you get aroused, going to light sleep and the cycle happens over and over again.   

Dental Treatment Options

One of the ways that this is treated is using a dental device that pulls the lower jaw forward, which is similar to what you use for snorers and mild sleep apnea patients. So I have the patients thrust their jaw forward and by putting the jaw forward, it also pulls the tongue forward and you can see a vast improvement in the caliber of the airway.   

Based on an extensive series of questionnaires, your physical examination, your past family history and the endoscopic evaluation, you can determine whether or not you need a sleep study. So if you undergo a sleep study and you are found to have sleep apnea, then it is treated like normal sleep apnea. That is a topic for another podcast in itself. But if you don’t officially meet the criteria for sleep apnea—meaning that your apnea/hypopnea index is less than 5 but you do have evidence of multiple arousals, then we can say that you may have UARS.   

You may be wondering, I just gave you a good explanation for UARS, but what can you DO about it?  In general, UARS is treated like sleep apnea. In general, the options are nasal breathing optimization, dental appliances, CPAP, or surgery, as a last resort.  Nasal optimization means if you have any degree of nasal congestion or obstruction, that’s dealt with, whether medically or surgically.  So, for most people, allergies are a very common reason that can be treated properly with medications or avoidance measures or even allergy shots. If you have a deviated septum, then that can be dealt with surgically if the medical options don’t work.  Dental appliances are also useful in people with sleep apnea and snoring in the same way it can be used for UARS patients, as well.  The mechanism is essentially the same: as the tongue starts to fall back—if it only falls back partially, then you create a vacuum effect upstream and the palate starts to collapse and then you get snoring. But in UARS patients, the tongue falls back completely, causing obstruction and more arousals. Some of the problems with a dental device include jaw pain, ear pain, and bite problems due to the nature of this device. 


CPAP, or Continuous Positive Airway Pressure, is actually the gold standard treatment for sleep apnea. In the original article that described UARS, CPAP was used successfully in many of these patients. The way CPAP works is that a small mask is placed tightly over your nose and a small amount of positive air pressure is gently blown in through your nose, stenting your airway open while you are sleeping at night. If you have tried and failed these conservative options, then there are surgical options as well.   

Case Example Success Story

Before we finish this evening’s discussion, let me just bring up an interesting case example which will illustrate my point. I had a patient, a young woman in her 30s, who came to see me with recurrent throat infections and was also found to be extremely tired and had depression, on anti-depressants. She also had severe cold hands and feet, low blood pressure with frequent lightheadedness and dizziness, recurrent sinus infections, migraines and chronic diarrhea. She was severely distraught because her overall health had deteriorated to the point where she couldn’t function normally at her job. A sleep study showed that she had mild sleep apnea, at 14 events every hour. She tried CPAP but couldn’t tolerate the mask. Then, she also refused a dental device because she had TMJ. Finally, after a long discussion we decided to perform sleep apnea surgery with her palate and tongue. 

We did a conservative procedure on her palate, called a uvulopalatal flap, as well as a tongue-based procedure. Six months later on a follow-up sleep study; her apnea/hypopnea index had dropped to .2, which is basically cured. But, more surprisingly, she noted that her cold hands and feet were gone, her diarrhea was much better and even her sinus headaches and migraines were better. On her last doctor’s exam, she noted also that her blood pressure had normalized and she wasn’t lightheaded or dizzy anymore. She was completely off her anti-depressants and reported a “life-changing experience.”   

This woman had classic UARS but because she also met the criteria for sleep apnea, was able to undergo definitive treatment. My guess is that, untreated for many years, she would have gained more weight eventually. Many of her UARS symptoms would have disappeared as the onset of sleep apnea signs and symptoms began to appear.   

UARS and Somatic Syndromes

One interesting study many years ago looked at UARS and its possible association with the somatic syndromes and these include a wide-ranging list of medical conditions like chronic fatigue syndrome, fibromyalgia, hypothyroidism, irritable bowel syndrome and more. Obviously, not all patients with the above conditions have UARS but based on this paradigm, I think it’s safe to say that a significant number of people with these conditions actually have UARS instead. People with these somatic syndromes all have in common some form of chronic fatigue, as well as an inability to sleep well. Obviously, more study is needed in this area.   

As you can see, UARS can potentially explain many symptoms. Typically, these patients see multiple doctors for various complaints without ever finding complete relief. In the end, some even lose faith in Western or allopathic medicine and look elsewhere in alternative or complimentary forms of treatment. UARS is a treatable condition. The first step is a thorough evaluation by someone who knows what to look for. 

If you want more information about UARS, as well as a more complete picture of why we have so much of these problems and what we can do about it, go to Amazon.com to take a look at my book, Sleep Interrupted, which describes everything in much more detail. 

That’s it for tonight’s podcast.  For more information, please visit doctorstevenpark.com. You can sign up for my email updates and newsletters as well at this address. 

Until next time, good night!