Created: 09/19/2013 6:41 PM KSTP.com
By: Kenny King
(ABC 6 NEWS) -- A sleep study is one of the key tests doctors use to diagnose of a condition called obesity hypoventilation syndrome, or OHS.
Mayo Clinic Pulmonary and Critical Care Dr. Eric Olson says, "OHS is a condition where people with greater than ideal body weight perpetually under breathe."
Dr. Olson says OHS is more dramatic at night, but it's also present during the day. It can happen to people who are obese, with a BMI of 30 or more, because their bodies can't compensate for the stress of the extra weight. Oxygen levels go down and carbon dioxide levels go up. Over the short term OHS, which is often accompanied by obstructive sleep apnea, causes poor sleep, headaches, daytime sleepiness and a general feeling of being unwell.
"Over the long haul you start to get complications related to the heart."
As oxygen levels drop, vessels in the lungs constrict, making it hard for the right side of the heart to pump blood from the extremities back to the lungs for oxygenation. Over time, the right ventricle becomes enlarged and eventually wears out, causing heart failure.
If you're diagnosed with OHS its important to get on the right treatment which means the use of a positive air pressure device. Either C-Pap or a Bi-level pressure device. C-Pap, which is also used for sleep apnea, keeps the throat open when you sleep by providing continuous in-ward flowing air pressure. A bi-level device boosts the breath taken by the patient. The bigger the breath, the more oxygen goes in and the more carbon dioxide goes out.
A sleep study can help determine the appropriate PAP device and settings.
"People who start PAP therapy feel better very quickly." Dr. Olson says you should see a healthcare provider if you are obese and have symptoms that include: snoring, halted breathing at night, waking up at night, daytime drowsiness, swollen legs or shortness of breath.