Obstructive sleep apnea causes decreased oxygen supply to lung and to brain,(due to brief period of apnea while breathing during sleep) , which causes you to wake up frequently during sleep, and less relaxed even in the morning. Over weight Is most common for this or deviated nasal septum(causes frequent wet nose and snoring). Consult ENT specialist to rule out deviated nasal septum,, or physician for over weight. There are other causes for snoring too,,, which are rare.