Sleep Apnea is a medical condition,which makes it difficult to sleep for some, as they are not breathing correctly, while for others, it can mean listening to snoring for quite a long time. Sleep apnea is most commonly also called 'obstructive' sleep apnea, which is the condition where you, as the person sleeping, stop breathing. As you stop breathing, you are not resting correctly, and this reduces the oxygen in the blood while you are sleeping.