Hypopneas are not quite apneas in that you don’t completely stop breathing. There are reductions in airflow or respiratory effort but no full cessation of breath. That means some air is still getting to your lungs. These reductions are called hypopneas. They are like putting part of your hand over the suction nozzle of the vacuum cleaner, for obstructive hypopneas. Central hypopneas would be more like running the vacuum on less electricity than is actually required. In both situations some air gets through but not enough to do a proper job. They are usually associated with a decrease in blood oxygen. Patients suffering from sleep apnea often have hypopneas and when hypopneas occur on their own, it usually means that sleep apnea is developing.
Like apneas, hypopneas come in three varieties:
Obstructive Hypopneas: During an obstructive hypopnea, there is a 50% decrease in airflow but respiratory effort remains intact. This means that there is only a partial occlusion in the upper airway.
Central Hypopneas: With a central hypopnea, there is a 50% reduction in both airflow and respiratory effort.
Mixed Hypopneas: Mixed hypopneas consist of both central and obstructive components. There is the initial central hypopnea followed by and obstructive hypopnea.
If you think you may be experiencing hypopneas, ask your medical doctor to refer you to a sleep clinic.
Thanks to L. Orr, BA, RPSGT for her help with this article.