Hypopnea: What to Know About This Sleep Disorder

You may have heard of sleep apnea. It’s a common disorder that affects more than 18 million American adults.

But you may not be familiar with its cousin, hypopnea. Apnea and hypopnea are different versions of a condition called obstructive sleep apnea hypopnea syndrome. Some people have both apnea and hypopnea.

Types of Hypopnea

Apnea and hypopnea are a lot alike but differ in key ways. Hypopnea is when you take in shallow breaths for 10 seconds or longer while asleep and your airflow is at least 30% lower than normal. But your breathing doesn’t totally stop since your airway is only partly blocked.

With apnea, your airways are fully obstructed so that you do stop breathing for 10 seconds or more during the night. With either case, you might wake up many times during your sleep to catch your breath without being aware.

Hypopnea has three types:

  • Central hypopnea, when air flow lessens and breathing slows
  • Obstructive hypopnea, when only air flow, not breathing, is lowered
  • Mixed hypopnea, which has periods of both central and obstructive hypopnea


Hypopnea can cut off your nighttime breathing by a third or more. That means less oxygen gets carried around your body. This can lead to symptoms that are similar to apnea. You may:

  • Feel unusually sleepy during the day
  • Snore loudly and awaken from sleep short of breath or with a headache
  • Lack energy
  • Have trouble remembering things or paying attention
  • Feel depressed or irritable


Several things can make you more likely to have hypopnea, including:

  • Weight. Extra pounds can build up fat in your neck and around the airway, impeding air flow.
  • Body structure. Some people are born with a small airway. Or your tonsils or adenoids in your throat might be larger than normal and take up extra space in your airway.
  • Age. Hypopnea is more common in people who are middle-aged or older.
  • Gender. Men are more likely to have hypopnea.
  • Genetics. If a family member has hypopnea, you may be more likely to have it.
  • Smoking or using alcohol.
  • Heart or kidney disease. When these conditions are advanced, fluid can build up in your neck and make it harder for you to breathe.



Your doctor may ask about your medical and family history. They also may check your weight, tonsils, or upper airway. Blood tests or ultrasound imaging may help rule out other conditions that could be causing your symptoms.

Your doctor may suggest a sleep study. You go to sleep attached to sensors that count how many times your breathing slows or stops in an hour. It also checks your heart rate, brain waves, blood oxygen levels, and other vital signs.

Your results can be matched against a scale called the apnea-hypopnea index (AHI), which shows the number of times you have apnea or hypopnea during one night.


The goal is to help you breathe easier during sleep. Untreated hypopnea may lead to other health problems, including high blood pressure, strokes, and accidents from being drowsy.

If an AHI shows you have moderate hypopnea, this means you have 15-30 events of shallow or slow breathing an hour. Severe hypopnea means this happens more than 30 times per hour. Mild cases are defined as 5-14 episodes. Moderate or severe scores may mean you need a CPAP machine (a (continuous positive airway pressure machine) while you sleep.

With a CPAP, you wear a mask over your nose that’s attached to a machine with a hose. It blows air into your nose to keep breathing from slowing while you sleep.

Other options include:

  • A mouthpiece to push your lower jaw forward during sleep or to stop your tongue from blocking your upper airway
  • Lifestyle changes, like losing weight, exercising, or quitting smoking or drinking
  • Sleeping on your side or stomach instead of your back
  • Avoiding sleep medications or sedatives

Your doctor may want to treat any blockage in your airway. This can involve surgery to remove extra tissue, such as the tonsils, or to move your jaw forward.

WebMD Medical Reference Reviewed by Carol DerSarkissian, MD on April 06, 2022



National Heart, Lung, and Blood Institute: “Sleep Apnea.”

National Sleep Foundation: “Sleep Apnea.”

Sleep Science and Practice: “Hypopnea Definitions, Determinants and Dilemmas: A Focused Review.”

Mayo Clinic Proceedings: “Obstructive Sleep Apnea-Hypopnea Syndrome.”

Mayo Clinic: “Obstructive Sleep Apnea.”

Avicenna Journal of Medicine: “Obstructive Sleep Apnea-Hypopnea Syndrome: Etiology and Diagnosis.”

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