Obesity Hypoventilation Syndrome

Obstructive Sleep Apnoea (OSA) is a common condition associated with overweight and obesity, but a lesser known lung condition also associated with overweight and obesity is ‘Obesity Hypoventilation Syndrome’ (OHS). Often, patients with OHS can also have OSA and suffer from both conditions. Let’s take a closer look at OHS and see what it does to the body, and how to manage it.

Obesity Hypoventilation Syndrome (OHS) is a breathing disorder that affects some people who have obesity. Normally, when we breathe in, we absorb the oxygen (O2) from the air to oxygenate the blood in our body. When we exhale we breathe out gaseous waste; this waste is carbon dioxide (CO2). In OHS, ventilation is impaired and there is a reduction in the O2 coming in and a reduction in the CO2 coming out. This results in LOW O2 levels in the blood, and HIGH CO2 levels in the blood. This is dangerous because it can be a life threatening condition! Lack of O2 can put a huge strain on the heart and blood vessels and increases mortality (risk of death.)

OHS is defined as a combination of obesity (BMI >30kg/m2), daytime high CO2 levels, and sleep disordered breathing. If it is suspected you may have OHS it is best to see a Respiratory and Sleep Physician who can perform the assessment required to diagnose the condition and who can provide part of the treatment.

Symptoms of OHS include:
• Daytime sleepiness
• Breathlessness
• Headache
• Low mood/depression
• Lack of energy
• Loud snoring
• Stopping breathing during sleep

Treatment includes ventilation support in an attempt to correct the O2 and CO2 levels in the body. This is usually in the form of a CPAP machine or with non-invasive ventilation devices. The most ideal definitive treatment is significant weight loss. This can be achieved through diet and lifestyle changes, psychological support, medications and/or bariatric surgery. 

At MedSurg Weight Loss we perform comprehensive assessments and if we suspect OHS we can arrange a review with our affiliated Respiratory Physician as well as support you to achieve weight loss to manage or reverse OHS.