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What Are the Signs and Symptoms of Obesity Hypoventilation Syndrome?

Many of the signs and symptoms of obesity hypoventilation syndrome (OHS) are the same as those of obstructive sleep apnea. This is because many people who have OHS also have obstructive sleep apnea.

One of the most common signs of obstructive sleep apnea is loud and chronic (ongoing) snoring. Pauses may occur in the snoring. Choking or gasping may follow the pauses.

Other symptoms include:

  • Daytime sleepiness
  • Morning headaches
  • Memory, learning, or concentration problems
  • Feeling irritable or depressed, or having mood swings or personality changes

You also may have rapid, shallow breathing. During a physical exam, your doctor might hear abnormal heart sounds while listening to your heart with a stethoscope. He or she also might notice that the opening to your throat is small and your neck is larger than normal.

Complications of Obesity Hypoventilation Syndrome

When left untreated, OHS can cause serious problems, such as:

  • Leg edema, which is swelling in the legs caused by fluid in the body's tissues.
  • Pulmonary hypertension, which is increased pressure in the pulmonary arteries. These arteries carry blood from your heart to your lungs to pick up oxygen.
  • Cor pulmonale, which is failure of the right side of the heart.
  • Secondary erythrocytosis, which is a condition in which the body makes too many red blood cells.
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Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans.

NHLBI Research Featured in HBO Documentary Series on Obesity

Hear people talk about their challenges and successes reaching and maintaining a healthy weight on the HBO Documentary Films series, “The Weight of the Nation,” which premiered in May 2012.

The film series spotlights the science behind obesity and how it affects the health of the nation. Watch the series to learn how citizens, groups, and policymakers are working to make a difference in their communities. The films stream free on the HBO Web site.

To learn more about the film series and related public awareness campaign, including how to host a local screening go to

January 27, 2012 Last Updated Icon

The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.