More than one billion people worldwide have obstructive sleep apnea, a reduction or complete blockage of airflow during sleep. Affected individuals can have excessive daytime sleepiness, fatigue, heavy snoring, and non-restful sleep. In a new study in the journal BMJ Open Respiratory Research, Penn State researchers collected data on over 42,000 people across the world. Those with obstructive sleep apnea were approximately twice as likely to experience sudden death than those who did not have the sleep condition. We have known that sleep apnea is linked to high blood pressure, heart disease, and many other health conditions. But this link to sudden death makes it more important to identify and treat individuals with the condition.