Obesity hypoventilation syndrome (patient information)

For the WikiDoc page for this topic, click here


 * Associate Editor-In-Chief: Mohammed A. Sbeih, M.D.[mailto:msbeih@perfuse.org] Phone:617-849-2629

Overview
Obesity hypoventilation syndrome (OHS) is a condition that occurs in obese people, in which poor breathing leads to lower oxygen levels and higher carbon dioxide levels in the blood.

What are the symptoms of Obesity hypoventilation syndrome?
The main symptoms of OHS are due to lack of sleep and include:

Symptoms of low blood oxygen level (chronic hypoxia) can also occur, such as shortness of breath or feeling tired after very little effort.
 * Excessive daytime sleepiness.
 * Falling asleep during the day.
 * Increased risk for accidents or mistakes at work.
 * Depression.

What causes Obesity hypoventilation syndrome?
The exact cause of OHS in unknown. Most (but not all) patients with the syndrome have a form of sleep apnea.

OHS is believed to result from both a defect in the brain's control over breathing, and excessive weight (due to obesity) against the chest wall, which makes it hard for a person to take a deep breath. As a result, the blood has too much carbon dioxide and not enough oxygen. People with OHS are often tired due to sleep loss, poor sleep quality, and chronic hypoxia.

Excess (morbid) obesity is the main risk factor.

When to seek urgent medical care?
Call your health care provider if you are very tired during the day, or have any other symptoms that suggest OHS.

Diagnosis
People with OHS are usually very overweight. Symptoms of OHS include:

Tests to confirm OHS include:
 * Bluish color in the lips, fingers, toes, or skin (cyanosis)
 * Signs of right-side heart failure (cor pulmonale), such as swollen legs or feet, shortness of breath, or feeling tired after little effort
 * Reddish complexion
 * A short, thick neck and small airway passage in the mouth

Doctors can tell OHS from obstructive sleep apnea by high carbon dioxide levels in the blood when a person is awake.
 * Sleep study
 * Lung (pulmonary) function
 * Arterial blood gas

Treatment options
The treatment involves breathing assistance using special machines (mechanical ventilation). Options include:

Other treatments are aimed at weight loss, which can reverse OHS.
 * Non-invasive mechanical ventilation (BiPAP or other modes) through a mask that fits tightly over the nose or nose and mouth (mainly for sleep)
 * Mechanical ventilation through an incision in the neck (tracheostomy)
 * Oxygen

Where to find medical care for Obesity hypoventilation syndrome?
Directions to Hospitals Treating Obesity hypoventilation syndrome

What to expect (Outlook/Prognosis)?
Untreated, it can lead to serious heart and blood vessel problems, severe disability, or death. Chronic sleeping problems may also increase the chance of having a motor vehicle accident.

Possible complications
Complications of OHS have to do with a lack of sleep, such as:

OHS can also include heart problems, such as:
 * Increased risk for accidents
 * Depression, agitation, irritability
 * Sexual dysfunction


 * Hypertension
 * Right heart failure (cor pulmonale)

Prevention
Maintain a healthy weight and avoid obesity.