This is a disorder patient suffer from where breathing begins and stops while sleeping repeatedly. Apnea happens when the throat muscles sporadically relax and block your upper airway while you sleep. Some side effects of apnea may include: snoring, headaches, high blood pressure, tiredness during the day and anxiety. When breathing has stopped, and oxygen is restricted to your heart and brain, the increased heart rate is what causes a person to wake up to hundreds of times during the night. This process is why one may feel very tired and drowsy during the day. If this condition is left untreated it can lead to heart disease, stroke, or mood disorders.