Obesity hypoventilation syndrome (OHS) — also called Pickwickian syndrome — is a serious breathing disorder that occurs in people living with obesity. Difficulty breathing can quickly affect your quality of life. It leads to fatigue, poor sleep, and heart problems. In some cases, it can even become life-threatening due to respiratory failure (when your lungs can’t get enough oxygen into your blood or get rid of enough carbon dioxide). That’s why getting help for OHS early really matters.

Paying attention to early signs of OHS can make a big difference. Do you feel sleepy during the day, snore loudly, wake up repeatedly during the night, or have shortness of breath? If you or someone you care about has these symptoms, it might be helpful to find an obesity specialist to help with diagnosis and treatment.

Let’s go over what the condition is, what it feels like, and what you can do to get treatment.

What Is Obesity Hypoventilation Syndrome?

The word “hypoventilation” means “decreased breathing.” Obesity hypoventilation syndrome may be diagnosed if you have these three factors:

• A body mass index (BMI) score of 30 or above
• Daytime hypercapnia (increased carbon dioxide levels, which rise in the blood when breathing is too shallow)
• Sleep-disordered breathing (such as obstructive sleep apnea, where breathing stops and starts many times while you sleep)

A diagnosis of OHS can only be made when other causes of decreased breathing, such as chronic obstructive pulmonary disease (COPD), are ruled out.

Why Does OHS Happen?

Currently, there isn’t a specific known cause of OHS. Researchers have found a few factors that may contribute to the condition:

• A larger body weight decreases the space the lungs can expand and puts extra pressure on the chest wall, which can make it harder to breathe.
• Fat cells release hormones — like leptin — which can change how your brain controls breathing. This may lead to slower or more shallow breathing, especially during sleep.
• Signals from the brain may not be effective at controlling the breathing rate.

These factors can all affect the respiratory system and may lead to OHS.

People with OHS also have changes in the way their body reacts to breathing problems. Normally, when there’s too much carbon dioxide or too little oxygen in the blood, the brain tells the body to breathe more. But for people with OHS, the brain doesn’t respond the same way. This means the person doesn’t breathe more, even when their body needs it.

Also, research shows people with OHS have about 20 percent more trouble moving air than people with obesity who don’t have OHS — and about 60 percent more than people with a BMI score in the normal range.

Who Gets OHS?

OHS happens in 1 out of every 260 people in the U.S. According to Cleveland Clinic, Black people are more affected by OHS than white people. Studies show OHS occurs in between 8 percent and 20 percent of people living with obesity. A study in the European Respiratory Review reported OHS pretty equally affects both men and women.

What Are the Symptoms of OHS?

Since OHS changes the way you breathe, it causes symptoms that affect your sleep at night as well as symptoms that carry over during the day.

At night, difficulty breathing can cause you to snore, gasp for air, and even have pauses in your breathing. Decreased breathing can lead to daytime symptoms as well, which include headaches, dizziness, daytime sleepiness, lack of energy, and depression. Some people with OHS may find themselves falling asleep while sitting, even in situations where attention is required, such as driving or watching a presentation.

A lot of OHS symptoms, including those listed above, are similar to those of obstructive sleep apnea. However, people with OHS, in contrast to those with obstructive sleep apnea, often have dyspnea (difficulty breathing) or a feeling of breathlessness during the day.

Another condition, called cor pulmonale, is more common in those with OHS than obstructive sleep apnea alone. Cor pulmonale is when the right side of the heart starts to fail. When the lungs are affected, as in OHS, the right side of the heart has a harder time pumping blood to the lungs. As with other heart failure conditions, this can lead to peripheral edema, which is swelling in the arms and legs.

What Should You Do if You Think You Have OHS?

If you think you have the symptoms of OHS listed above or you’re concerned about your health in any way, it’s best to consult your medical provider. They can order tests to help you get a diagnosis and any necessary treatments.

Getting an OHS Diagnosis

When you see your healthcare provider, they’ll take a thorough history of your symptoms and concerns. They will order a blood test to measure arterial blood gases (the oxygen and carbon dioxide levels in your blood). They will also likely measure your oxygen saturation levels from a pulse oximetry sensor hooked up to your finger.

To rule out other causes of your symptoms, your doctor might take a chest X-ray and ask you to perform some pulmonary function tests to examine your lungs. A sleep study, called a polysomnography, can help your medical team see if you have sleep apnea and sleep hypoventilation by evaluating your breathing patterns as you rest.

If you show signs of heart failure, your doctor might order some heart tests, such as an electrocardiogram (to measure the heart’s electrical activity) or an echocardiogram (a noninvasive ultrasound scan). Your medical team will guide you through the testing process and answer any questions you might have along the way.

Treatment for OHS

Treatment for OHS includes finding ways to help you breathe at night while you’re asleep. Noninvasive ventilation devices that help keep your airways open and improve lung function include a continuous positive airway pressure (CPAP) machine and a bilevel positive airway pressure (BiPAP) machine:

• CPAP delivers the same pressure as you breathe out and in and is usually the first line of treatment.
• BiPAP delivers more pressure when you’re breathing in.

If you’re prescribed a PAP machine, it’s important you follow your doctor’s instructions about how to use it. In rare cases, if one of these noninvasive treatments doesn’t work, your doctor would need to do a tracheostomy, which creates a hole in your neck to help you breathe.

Weight loss is another key aspect of OHS treatment. Since weight loss can be challenging and dangerous if not done properly, it’s recommended to have your weight loss plan supervised by a team of medical professionals and tailored to your own needs and conditions. Healthy eating, physical activity, and weight loss medications may be part of this plan.

In some cases, your doctor might recommend a bariatric (weight loss) surgery such as gastric bypass surgery. Though bariatric surgery can be helpful with the weight loss side of treatment, keep in mind this surgery comes with various risks and complications. Your doctor will guide you on which treatment options will be best for your situation.

If you have other health conditions related to obesity, your doctor might add more treatments. Since OHS can lead to heart problems, you may also need medicine to support your heart health.

Outlook for People With OHS

Untreated OHS can lead to shortened life expectancy, especially for those with other health issues. Complications with OHS include cardiovascular conditions such as increased blood pressure, right-sided heart failure, and angina (chest pain related to the heart not getting enough oxygen). Because of these increased health risks, it’s important to seek medical attention early and get treatment. Diet and lifestyle changes and weight loss can reduce symptoms for some people. Cleveland Clinic estimates early treatment with a breathing device can reduce the mortality rate of OHS by 10 percent.

Living with OHS isn’t easy, but you’re not alone. Your doctors are there to help you breathe better, protect your heart, and feel stronger. Regular check-ins will help your doctors make sure your treatment is working and adjust it if needed.

Taking care of your health takes courage. Ask questions, speak up, and remember you are strong and you deserve care that works for you.

Talk With Others Who Understand

On MyObesityTeam, the social network for people with obesity and their loved ones, more than 57,000 members come together to ask questions, give advice, and share their stories with others who understand life with obesity.

Do you have trouble breathing at night? Have you had success managing symptoms with any of the treatments mentioned in this article? Share your experience in the comments below, or start a conversation by posting on your Activities page.