Sleep apnea is a serious sleep disorder that requires treatment. If left untreated, it can lead to poor output in your daily activities; academic underachievement in children and adolescents, etc. Further, this disorder can also cause a number of other ailments such as hypertension, stroke, cardiomyopathy, heart failure and diabetes. Read on to know the causes, symptoms and long term effects of this condition. Sleep apnea is characterized by repeated stops in the breathing pattern during sleep. It can affect anyone, but is mostly seen in middle-aged men. This serious condition is of two types: Obstructive sleep apnea: It occurs when there is a blockage in the air passage between the nose and lungs. Central sleep apnea: This happens due to faulty brain signals while regulating breathing. In adults, it is usually caused due to excess weight, bulky tongue, the lax soft tissue in the pharynx and nasal obstruction. When we breathe, the air flows from the nose to the pharynx, through the voice box to the windpipe and finally reaches the lungs. Obstruction at any of these levels may cause sleep apnea, although the most common location is the throat. Sleep apnea in adults is often suspected when the spouse of the patient complains of inability to sleep due to the partner's snoring. Other symptoms in adults include frequent awakening at night due to interrupted sleep, fatigue and feeling sleepy during the day, mental fatigue, confusion, irritability and forgetfulness. Chronic cough is another obvious symptom that has been associated with sleep apnea. Chronic lack of oxygen due to untreated sleep apnea leads to increased inflammation at the cellular level. This has been linked to diabetes, hypertension, obesity, increased risk of stroke, heart attack and cancer. Sleep apnea is a dangerous disease that slowly affects all systems of the body. However, it can be avoided, even reversed if it gets diagnosed and treated at an early stage.