Obesity hypoventilation syndrome, or Pickwickian syndrome, is a breathing condition some people with obesity experience. Symptoms include breathlessness and fatigue. Treatment can involve lifestyle changes and a PAP machine.

Obesity hypoventilation syndrome affects a person’s breathing pattern and can affect how their brain controls their breathing. If left untreated, it can lead to life threatening complications.

However, not everyone with obesity experiences hypoventilation.

This article further explains what obesity hypoventilation syndrome is. It also goes over the symptoms, causes, and treatment for the condition.

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Obesity hypoventilation syndrome is a breathing condition that affects some people with obesity. Usually, when a person breathes, they exhale carbon dioxide. This is a result of the body breaking down food to use as energy. With obesity hypoventilation syndrome, however, a person can end up with too much carbon dioxide and too little oxygen in their blood.

Some researchers define obesity hypoventilation as a combination of obesity, daytime hypercapnia or high levels of carbon dioxide in the blood, and disordered breathing during sleep.

The World Health Organization (WHO) states that a person will receive a diagnosis of obesity when they have a body mass index (BMI) of 30 or more. BMI is a standard screening tool commonly used to diagnose obesity.

BMI is a calculation of someone’s body fat based on height and weight. However, studies have shown that BMI can be a poor indicator of overall body fat percentage. This can be misleading because it does not take into account a person’s overall body composition. BMI measurements overlook muscle mass, bone density, and other considerations.

A person should speak with their doctor about other body fat measurement options.

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Obesity can increase a person’s risk of many health conditions, including:

It can also cause breathing difficulties, including obesity hypoventilation syndrome.

Learn more about obesity.

Some common symptoms of obesity hypoventilation syndrome include:

  • fatigue or extreme tiredness
  • breathlessness
  • dizziness
  • sluggishness or sleepiness during the day
  • headaches

Someone with obesity hypoventilation syndrome may also notice that they snore loudly, choke or gasp, or have difficulty breathing at night. These symptoms may worsen over time.

This is a condition that is known as sleep apnea. Obesity is a common risk factor for sleep apnea. According to a 2019 review, around 90% of people with severe obesity also experience sleep apnea.

Learn more about sleep apnea.

Having obesity puts a person at risk of developing obesity hypoventilation syndrome. However, it is unknown exactly why the condition affects some people with obesity and not others.

Obesity hypoventilation syndrome may occur due to excess fat around the neck, chest, or abdomen that makes breathing difficult. This may also produce hormones that affect breathing patterns.

Individuals with obesity hypoventilation syndrome may also experience issues with how their brain controls their breathing.

Learn more about breathing difficulties.

Many people do not receive an obesity hypoventilation syndrome diagnosis until they experience chronic respiratory failure or receive a referral to a pulmonary or sleep specialist.

However, if left untreated, it can lead to life threatening complications. This means it is important for a person to tell their doctor about any symptoms and breathing difficulties they may experience.

To diagnose obesity hypoventilation syndrome, a healthcare professional will typically begin with a physical exam. They will also generally include:

  • taking a medical history
  • questioning about issues such as breathlessness, sleep patterns, and daytime sleepiness
  • measuring height and weight
  • calculating BMI
  • measuring waist and neck circumference

The healthcare professional may also recommend lung tests to check how well a person’s lungs are working and the amount of oxygen and carbon dioxide in their body.

If a healthcare professional believes a person may also be experiencing sleep apnea, they may recommend a sleep study as well.

Find BMI calculators and charts here.

Treatment for obesity hypoventilation syndrome typically begins with lifestyle changes. These changes generally include getting to and maintaining a moderate weight and increasing physical activity.

If a person is also experiencing sleep apnea, a doctor may recommend treatment with a continuous positive airway pressure (CPAP) machine or another breathing device. These devices help keep an individual’s airways open and increase oxygen levels while sleeping.

Other treatments may include weight-loss surgery and medications.

A person can speak with their healthcare professional to discuss the most effective treatment options for their circumstances.

Learn more about potential treatments for obesity.

Adithya Cattamanchi, MD, has reviewed these frequently asked questions about obesity hypoventilation syndrome.

Does obesity hypoventilation syndrome go away?

With treatment and weight loss, symptoms of obesity hypoventilation syndrome can decrease or go away completely.

How common is obesity hypoventilation syndrome?

The exact prevalence of obesity hypoventilation syndrome is unknown. However, some studies estimate that approximately 10% of people with severe obesity have the syndrome.

Can hypoventilation cause death?

If left untreated, hypoventilation can cause serious complications and death.

Obesity hypoventilation syndrome is a breathing condition that affects some people with obesity. It causes carbon dioxide levels in the blood to be too high and oxygen levels to be too low.

Many people with obesity hypoventilation syndrome also experience sleep apnea. This is a condition when a person’s breathing stops for a period of time during the night.

Treatment for obesity hypoventilation syndrome includes weight loss, regular physical activity, and using a CPAP or noninvasive ventilation machine. Other treatment options may include weight loss surgery or medications.

Individuals can speak with their doctor about any symptoms they are experiencing and the most effective treatment options for their circumstances.