Key Takeaways
- What Is Hypopnea: Hypopnea is a sleep-breathing disorder characterized by shallow or limited breathing during sleep, which results in reduced oxygen intake. It is similar to sleep apnea but involves partial rather than complete cessation of breathing.
- Types of Hypopnea: There are three types of hypopnea—obstructive hypopnea, central hypopnea, and mixed hypopnea. Obstructive hypopnea is the most common and is caused by blocked airways, while central hypopnea results from a disconnect between the brain and the body’s breathing control. Mixed hypopnea combines elements of both.
- Symptoms of Hypopnea: Hypopnea can have various symptoms, including excessive daytime sleepiness, snoring, moodiness, and difficulty concentrating. It is often associated with risk factors such as obesity, neck size, family history, gender, nasal congestion, and certain medications. Left untreated, hypopnea can lead to complications such as weight gain, cardiovascular disease, and disrupted sleep.
Most of us take breathing for granted. It’s one of those things that our body simply does, without us having to think about it, and each lungful of air delivers oxygen to the cells throughout our body. This oxygen is indispensable to our body’s metabolic processes and, therefore, to life.
But for people with hypopnea, taking a full breath during sleep isn’t a given. Instead, people with hypopnea take low, shallow breaths, severely limiting the amount of oxygen to which their bodies have access. It’s a sleep disorder similar to sleep apnea.
In this article, we explore this condition, digging into hypopnea’s symptoms, diagnosis, and treatment to better understand how and why breathing, at least during sleep, is not always as natural as we might believe.
What is Hypopnea?
Hypopnea Verified Source American Academy of Sleep Medicine Society focused on sleep medicine and disorders, and the AASM is who authorizes U.S. sleep medicine facilities. View source is a sleep breathing disorder in which a person’s breathing becomes temporarily limited or shallow during sleep. Because people with hypopnea do not take deep or even normal-level breaths during these episodes, the oxygen Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source they receive through the air is limited.Episodes of hypopnea last 10 seconds or more each, and airflow drops Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source as much as 90% in each breath. Unsurprisingly, the longer each episode lasts, the worse the effects. Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source Overall, these events can result in a 3-4% decrease in blood oxygen levels as well as fragmented sleep, as the body wakes itself up in an effort to restore normal breathing.
Hypopnea is closely related to sleep apnea, a condition in which people completely stop breathing during sleep. The two often occur together, and if you have hypopnea, there’s a pretty good chance that you either have or will develop sleep apnea as well.
Three Types of Hypopnea
There are three known types of hypopnea. The first and most common is obstructive hypopnea. Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source It is also known as obstructive sleep apnea-hypopnea syndrome Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source or OSAHS.
For those with OSAHS, partially blocked airways limit the flow of air in and out of the lungs. During sleep, the muscles and other tissues relax into the upper airways, closing them off. Air still moves in and out, but at a much lower volume than expected.
Central hypopnea Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source is caused not by a blocked airway but by a disconnect between the brain and the body. With central hypopnea, the muscles that control breathing don’t receive the necessary instructions to breathe properly, resulting in shallow breaths. Studies suggest that Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source damage to the brainstem may play a role in central hypopnea.The third type of hypopnea some patients experience is a combination of obstructive and central hypopnea. Patients with mixed hypopnea Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source experience shallow breathing due to both restricted airways and a lack of signals.
Even though it contains elements of central hypopnea, mixed hypopnea is generally considered a condition within OSAHS.
Hypopnea vs. Sleep Apnea: Similarities and Differences
Hypopnea and sleep apnea are very similar conditions in that they affect the quantity or quality of the breath during sleep. While breathing is limited in hypopnea, it stops entirely with sleep apnea.
The only practical difference between obstructive sleep apnea and hypopnea is whether the airway is partly or entirely closed. OSAHS encompasses both conditions, and patients may experience a combination of apnea and hypopnea events during the night. Because of this, some researchers suggest that the differences between the two Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source are not significant enough to warrant studying or addressing them separately.
Symptoms of Hypopnea
Hypopnea occurs during sleep, so it’s not always apparent that a person suffers from the condition. Even more, the daytime symptoms of hypopnea often mirror other widespread issues like stress and hypothyroidism, making it all too easy to overlook their real cause.
Common symptoms of hypopnea include:
- Excessive daytime sleepiness, even falling asleep
- Feeling tired upon waking
- Choking or gasping during sleep
- Frequent headaches
- Moodiness and irritability
- Trouble concentrating or focusing throughout the day
- Weight gain or difficulty losing weight
Snoring is another common symptom of an obstructive breathing disorder. Specifically, loud snoring is often another indication of airways that are blocked off. Those obstructions cause disturbances in the air, which translate into the snore sounds that we hear.
Risk Factors for Hypopnea
The risk factors for hypopnea are very similar to those of sleep apnea. They include:
- Obesity: Excess fat creates additional pressure and tissue around the chest and upper airways, especially the neck. Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source
- Size of neck/facial structure: People born with a small airway, larger than usual tonsils, or a natural obstruction are more at risk for the condition.
- Family History: If a family member has hypopnea, you are more likely to have it. Genetic predisposition may be closely related to other genetic factors such as facial structure.
- Gender: Hypopnea is more common in men.
- Congested nasal passages, as from a cold or allergies: Inflammation of the airways or excess mucus can reduce or limit airflow temporarily or permanently.
- Age: Hypopnea is more common in adults who are middle-aged or older.
- Heart/kidney disease: advanced conditions can cause fluid buildup in the neck, impacting airflow.
The use of certain medications like opioids can also Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source contribute to the experience of hypopnea.
Complications of Hypopnea
Left untreated, hypopnea can contribute to the development or progression of other conditions.
Obesity and Weight Gain
The relationship between weight and sleep disorders is complex. Excess weight is a significant risk factor for obstructive hypopnea. In addition, weight gain is a common side effect of sleep conditions such as hypopnea and sleep apnea. The link between weight and sleep apnea and similiar breathing conditions is still being studied.
Without adequate sleep, the body does not produce the right balance of hormones to manage hunger. This can result in disordered eating, leading to weight gain and making it difficult to manage or lose weight. Obesity, Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source in turn, is associated with many health concerns: diabetes, chronic disease, arthritis, liver and kidney disease, depression, and more.
Cardiovascular Disease
In addition, hypopnea has been associated with an increased rate of cardiovascular problems. Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source The exact reasons for the connection aren’t fully understood. Still, apnea and hypopnea are linked to several life-threatening conditions, including arrhythmia, hypertension, stroke, and even heart failure.
Frequent Nighttime Waking
Chronic fragmented sleep can cause a number of problems as well. People with regularly disrupted sleep, as from untreated hypopnea, rarely get the rest they need.
This sleep disturbance Verified Source ScienceDirect One of the largest hubs for research studies and has published over 12 million different trusted resources. View source translates into a reduced quality of life. Patients report extreme daytime sleepiness and, often, compromised performance at work or in school, like reaction time, short-term memory, and cognitive functioning are impaired.
Moreover, not getting enough quality sleep can impact your immune system, Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source making you more susceptible to illness. It also increases your risk Verified Source Mayo Clinic Ranked #1 hospital by U.S. News & World Report and one of the most trusted medical institutions in the world. The staff is committed to integrated patient care, education, and research. View source of being in a car accident or experiencing an injury at work.
Diagnosis for Hypopnea
Your doctor will likely ask you some questions about your sleep patterns and general health to diagnose hypopnea. They may ask you to keep a sleep diary for a couple of weeks or perform tests to rule out any other conditions that could be causing your symptoms.
Partners can also be a valuable resource in identifying the presence of obstructive hypopnea or apnea. Between loud snoring and the gasping or choking that sleep apnea and hypopnea patients often experience, the patient’s partner may first notice that there is a problem, as their own sleep can be disturbed by the symptoms of the condition. One study even found that after treatment, Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source quality of life improved for both patients and their partners.
If hypopnea or another sleep condition is suspected, your doctor will usually recommend a sleep study, also called a polysomnography. Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source Sleep studies are generally conducted overnight at a medical facility, where a specialist will monitor your brain and body activity throughout the night to identify any concerning patterns or abnormalities.
In some cases, an at-home sleep study Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source may also be an option, though it may not be possible depending on what vitals need to be measured.
During the study, a specialist will measure the number of hypopnea or apnea you experience each hour. The presence and severity of the condition are determined using the apnea-hypopnea index Verified Source Harvard Health Blog run by Harvard Medical School offering in-depth guides to better health and articles on medical breakthroughs. View source (AHI).
Five or fewer hypopnea episodes per hour are considered normal and do not require a diagnosis or treatment. Doctors use the AHI as follows to diagnose mild to severe hypopnea:
- Mild hypopnea: 5-14 episodes per hour
- Moderate hypopnea: 15-30 episodes per hour
- Severe hypopnea: 30+ episodes per hour
During the sleep study, your blood oxygen levels will also be monitored. The Respiratory Disturbance Index (RDI) may further be used to look for other breathing irregularities.
Treatment of Hypopnea
For mild cases of hypopnea, a few lifestyle changes may be enough to reduce the frequency and severity of symptoms. Moderate to severe hypopnea are more serious. Additional or even lifelong treatment may be required to manage it effectively.
Standard hypopnea treatment options include CPAP machines, lifestyle changes such as weight loss, surgery, or the use of oral devices. Central hypopnea patients may also benefit from medications to manage the condition.
CPAP Machines
CPAP stands for Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source continuous positive airway pressure and is often used to treat moderate to severe obstructive or central hypopnea and apnea.CPAP machines work by pushing air through the airways to keep them open during sleep. This helps to ensure that air can flow freely, allowing a full breath. While sleeping, users wear a mask that covers the nose, mouth, or both. A hose connects the mask to a CPAP machine that delivers the air.
Professor Dimitriou also states that “CPAP therapy has been linked with a number of positive outcomes, in particular increase in physical activities. However, simultaneous changes in individual habits might result in even more significant improvements in health.”
Lifestyle Adjustments
Sleep disorders can often be managed well with lifestyle changes, and hypopnea is no exception.
Weight Loss
Studies have found that weight loss is one of the most important changes an obstructive hypopnea patient can make to reduce the severity of their symptoms. In one study of sleep apnea and hypopnea, a 10% weight loss resulted in a 26% improvement in AHI results.
Changing Sleep Position
Obstructive hypopnea patients who typically sleep on their back may find that switching to their side or stomach may also help to reduce symptoms. Some sleeping positions better support good airflow than others, and it may take some experimentation to find the most comfortable and effective sleeping position for you.
Positional therapy techniques Verified Source American Academy of Sleep Medicine Society focused on sleep medicine and disorders, and the AASM is who authorizes U.S. sleep medicine facilities. View source can help to discourage sleeping on the back. These include the tennis ball technique, Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source a method in which a tennis ball is strapped to the back, making it uncomfortable to roll onto your back during sleep.Other Lifestyle Changes
Other lifestyle changes that experts have suggested to improving hypopnea Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source include:
- Eating a healthy diet
- Avoiding the use of sleep medications or sedatives
- Upgrading to a mattress for sleep apnea and pillows to support open airways
Surgery
For patients with severe obstructive hypopnea, surgery may be an option. Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source Surgical methods include removing extra tissue, such as enlarged tonsils, or even moving the jaw forward. The long-term effectiveness of these measures is still being studied, with some studies suggesting that other treatment options may be more valuable. For that reason, surgery may be the last resort when other treatments don’t work as hoped.
Oral Devices
One less permanent option to reduce sleep hypopnea symptoms is the use of oral or nasal devices. Oral devices are similar to mouthguards, and they work to keep the airway open by expanding or stabilizing it.
Central Sleep Apnea Treatments
The methods used to effectively Verified Source Mayo Clinic Ranked #1 hospital by U.S. News & World Report and one of the most trusted medical institutions in the world. The staff is committed to integrated patient care, education, and research. View source treat central hypopnea sometimes vary from those for obstructive hypopnea.
There are some significant differences between obstructive and central sleep apnea, from causes to effects. With central hypopnea, there’s nothing in the way of the breath being obstructed; a full breath just isn’t happening as it should during sleep.
Doctors may recommend the use of supplemental oxygen or medication to encourage breathing. If another condition has been identified as the cause of hypopnea, addressing those issues may resolve or improve hypopnea symptoms as well. Reducing the use of certain medications may further help to ease hypopnea symptoms.
FAQs
What is the main difference between an apnea and a hypopnea?
Hypopneas and apneas are very similar since they both affect your breathing while you sleep. Some people may even have both conditions at the same time, which is called obstructive sleep apnea-hypopnea syndrome (OSAHS).
What makes a hypopnea episode different from an apnea episode is that a hypopnea is only a partial loss of breathing. Your airway is not completely obstructed, which technically isn’t as severe as an apnea. With apnea episodes, you experience a total loss of breathing for 10 seconds or longer.
Is hypopnea as bad as apnea?
Generally, apneas are considered worse than hypopneas. With apneas, your breathing is completely impaired for 10 seconds or longer. But with hypopneas, your breathing is only partially impaired.
A complete loss of breathing is, unsurprisingly, more dangerous and stressful on your body than a partial loss of breathing. Regardless, both hypopneas and apneas can lead to cardiovascular diseases, obesity and weight gain, and chronic sleep problems.
Can hypopnea be cured?
Yes, many milder cases of hypopnea can go away with proper lifestyle changes and medical treatments when needed. Treatment can include using a CPAP machine at night, losing weight through diet and exercise, or switching your sleeping position.
With more severe cases of hypopnea, treatment can take years before the condition goes away. Treatment for severe hypopnea includes surgery, using supplemental oxygen, taking medication, and sleeping with a CPAP machine.
How many hypopneas per hour is normal?
Hypopneas are episodes of partial loss of breath for 10 seconds or longer while sleeping. Experiencing five hypopnea episodes or less per hour is considered normal for adults. In this case, you won’t need any diagnosis or treatment. Any more than five hypopnea episodes is when you should speak to your doctor for proper care.
What is the apnea-hypopnea score?
The apnea-hypopnea score (AHI) is a rating system used to determine the presence and severity of your hypopnea or apnea. It’s the number of times you have apnea or hypopnea episodes per hour per night.
The ranking is as such:
- Normal sleep: 5 episodes or less per hour
- Mild hypopnea: 5-14 episodes per hour
- Moderate hypopnea: 15-30 episodes per hour
- Severe hypopnea: 30+ episodes per hour
Conclusion
Hypopnea is a medical condition in which a person experiences frequent episodes of shallow breathing while sleeping. The condition is often chronic but can be managed through the use of medical devices, surgery, or simple lifestyle changes. These methods can improve the quality of sleep and, in turn, the quality of life in individuals diagnosed with hypopnea.
About the author
Carolyn Rousch is a freelance lifestyle writer and hobby photographer based in Tucson, Arizona. With a master's degree in data analytics from Texas A&M University, Carolyn brings a unique perspective to her writing. Her passion for helping people embrace their best lives drives her interest in sleep and well-being. Carolyn's expertise on sleep paralysis, as showcased in her article "Everything You Need to Know About Sleep Paralysis," reflects her dedication to delivering valuable and reliable information.
View all posts