Obesity Hypoventilation Syndrome

Also known as Pickwickian Syndrome
Obesity hypoventilation syndrome is a breathing disorder that affects some people who have been diagnosed with obesity. The syndrome causes you to have too much carbon dioxide and too little oxygen in your blood. Without treatment it can lead to serious and even life-threatening health problems.

It is not clear why obesity hypoventilation syndrome affects some people who have obesity and not others. Extra fat on your neck or chest or across your abdomen can make it difficult to breathe deeply and may produce hormones that affect your body’s breathing patterns. You may also have a problem with the way your brain controls your breathing. Most people who have obesity hypoventilation syndrome also have sleep apnea.

You can help prevent this condition by maintaining a healthy weight. If you have been diagnosed with obesity, your doctor may screen you for obesity hypoventilation syndrome by measuring your blood oxygen or carbon dioxide levels.

If you have obesity hypoventilation syndrome, you may feel sluggish or sleepy during the day, have headaches, or feel out of breath. You or a loved one may notice you often snore loudly, choke or gasp, or have trouble breathing at night. Your symptoms may get worse over time. Complications of obesity hypoventilation syndrome include pulmonary hypertension; right heart failure, also known as cor pulmonale; and secondary erythrocytosis.

To diagnose obesity hypoventilation syndrome, your doctor will perform a physical exam to measure your weight and height, calculate your body mass index (BMI), and measure your waist and neck circumference. Your doctor may perform other tests such as pulmonary function tests, sleep studies, a chest X-ray, or an arterial blood gas or serum bicarbonate test. Other blood tests may help rule out other causes or be used to plan your treatment. You may be diagnosed at the hospital if you have trouble breathing and go to the emergency room with respiratory failure. You may be diagnosed from tests routinely performed before a surgery.

If you are diagnosed with obesity hypoventilation syndrome, your doctor may recommend healthy lifestyle changes, such as aiming for a healthy weight and being physically active. You may also need a continuous positive airway pressure (CPAP) machine or other breathing device to help keep your airways open and increase blood oxygen levels. Other treatments may include weight loss surgery, medicines, or a tracheostomy.

To prevent complications, use your CPAP device as instructed and continue with your doctor’s recommended healthy lifestyle changes. Tell your doctor about new signs and symptoms, such as swelling around your ankles, chest pain, lightheadedness, or wheezing. Talk to your doctor if you will be flying or need surgery, as these situations can increase your risk for serious complications.

Visit Obesity Hypoventilation Syndrome for more information about this topic.

Participate in NHLBI Clinical Trials

We lead or sponsor many studies aimed at preventing, diagnosing, and treating heart, lung, blood, and sleep disorders.

More Information

Non-NHLBI resources
- Obesity Hypoventilation Syndrome