BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuObesity hypoventilation syndrome (OHS)Pickwickian syndrome Obesity hypoventilation syndrome (OHS) causes poor breathing in some people with obesity. It leads to lower oxygen and higher carbon dioxide levels in the blood. Causes The exact cause of OHS is not known. It is believed that OHS results from a defect in the brain's control over breathing. Excess weight against the chest wall also makes it harder for the muscles to draw in a deep breath and to breathe quickly enough. This worsens the brain's breathing control. As a result, the blood contains too much carbon dioxide and not enough oxygen. Symptoms The main symptoms of OHS are due to lack of sleep and include:Poor sleep quality Sleep apnea Sleep apneaObstructive sleep apnea (OSA) is a problem in which your breathing pauses during sleep. This occurs because of narrowed or blocked airways.ImageRead Article Now Book Mark Article Daytime sleepiness Depression DepressionDepression may be described as feeling sad, blue, unhappy, miserable, or down in the dumps. Most of us feel this way at one time or another for shor...ImageRead Article Now Book Mark Article Headaches TirednessSymptoms of low blood oxygen level (chronic hypoxia) and high carbon dioxide can occur. Symptoms include shortness of breath or feeling tired after little effort. Exams and Tests People with OHS have obesity (body mass index of 30 or greater). A physical exam may show:Bluish color in the lips, fingers, toes, or skin (cyanosis) CyanosisA bluish color to the skin or mucous membrane is usually due to a lack of oxygen in the blood. The medical term is cyanosis.ImageRead Article Now Book Mark Article Reddish skin Signs of right-sided heart failure (cor pulmonale), such as swollen legs or feet, shortness of breath, or feeling tired after little effort Cor pulmonaleCor pulmonale is a condition that causes the right side of the heart to fail. Long-term high blood pressure in the arteries of the lung and right ve...ImageRead Article Now Book Mark Article Signs of extreme sleepinessTests used to help diagnose OHS include:Arterial blood gas Arterial blood gasBlood gases are a measurement of how much oxygen and carbon dioxide are in your blood. They also determine the acidity (pH) of your blood.ImageRead Article Now Book Mark Article Chest x-ray or CT scan to rule out other possible causes Lung function tests (pulmonary function tests) Sleep study (polysomnography) Sleep study (polysomnography)Polysomnography is a sleep study. This test records certain body functions as you sleep, or try to sleep. Polysomnography is used to diagnose sleep...ImageRead Article Now Book Mark Article Echocardiogram (ultrasound of the heart)Health care providers can tell OHS from obstructive sleep apnea because a person with OHS has a high carbon dioxide level in their blood when awake. Treatment Treatment involves breathing assistance using special machines (mechanical ventilation). Options include:Noninvasive mechanical ventilation such as continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) through a mask that fits tightly over the nose or nose and mouth (mainly for sleep) Continuous positive airway pressure (CP...Positive airway pressure (PAP) treatment uses a machine to pump air under pressure into the airway of the lungs. This helps keep the windpipe open d...ImageRead Article Now Book Mark Article Oxygen therapy Breathing help through an opening in the neck (tracheostomy) for severe cases TracheostomyA tracheostomy is a surgical procedure to create an opening through the neck into the trachea (windpipe). A tube is most often placed through this o...ImageRead Article Now Book Mark Article Treatment is started in the hospital or as an outpatient. Other treatments are aimed at weight loss, which can reverse OHS, although it is often difficult to achieve. Outlook (Prognosis) Untreated, OHS can lead to serious heart and blood vessel problems, severe disability, or death. Possible Complications OHS complications related to a lack of sleep may include:Depression, agitation, irritability Increased risk for accidents or mistakes at work Problems with intimacy and sex OHS can also cause heart problems, such as:High blood pressure (hypertension) HypertensionBlood pressure is a measurement of the force exerted against the walls of your arteries as your heart pumps blood to your body. Hypertension is the ...ImageRead Article Now Book Mark Article Right-sided heart failure (cor pulmonale) High blood pressure in the lungs (pulmonary hypertension) Pulmonary hypertensionPulmonary hypertension is high blood pressure in the arteries of the lungs. It makes the right side of the heart work harder than normal.ImageRead Article Now Book Mark Article When to Contact a Medical Professional Contact your provider if you are very tired during the day or have any other symptoms that suggest OHS. Prevention Maintain a healthy weight. Use your CPAP or BiPAP treatment as your provider prescribed.Open ReferencesReferencesMalhotra A, Powell F. Disorders of ventilatory control. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 80.Mokhlesi B, Tamisier R. Obesity-hypoventilation syndrome. In: Kryger M, Roth T, Goldstein CA, Dement WC, eds. Principles and Practice of Sleep Medicine. 7th ed. Philadelphia, PA: Elsevier; 2022:chap 138.Mokhlesi B, Masa JF, Brozek JL, et al. Evaluation and management of obesity hypoventilation syndrome. An official American Thoracic Society clinical practice guideline. Am J Respir Crit Care Med. 2019;200(3):e6-e24. PMID: 31368798 pubmed.ncbi.nlm.nih.gov/31368798/.AllVideoImagesTogRespiratory system - illustration Air is breathed in through the nasal passageways, travels through the trachea and bronchi to the lungs.Respiratory systemillustrationRespiratory system - illustration Air is breathed in through the nasal passageways, travels through the trachea and bronchi to the lungs.Respiratory systemillustrationRelated Information Obstructive sleep apnea - adults(Condition)Respiratory acidosis(Condition)Blue discoloration of the skin(Symptoms)High blood pressure - adults(Condition)Obstructive sleep apnea(In-Depth)High blood pressure(In-Depth) Review Date: 8/1/2021 Reviewed By: Denis Hadjiliadis, MD, MHS, Paul F. Harron, Jr. Associate Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. 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