What is obstructive sleep apnea?What are the main signs and symptoms of obstructive sleep apnea?How is obstructive sleep apnea diagnosed?What are some of the main medical treatments for obstructive sleep apnea?Have any supplements been studied for obstructive sleep apnea?How could diet affect obstructive sleep apnea?Are there any other treatments for obstructive sleep apnea?What causes obstructive sleep apnea?How are sleep studies performed?