Obstructive Sleep Apnea occurs in all age groups and both sexes, but there are a number of factors that increase risk, including having a small upper airway (or large tongue, tonsils or uvula), being overweight, having a recessed chin, small jaw or a large overbite, a large neck size (17 inches or greater in a man, or 16 inches or greater in a woman), smoking and alcohol use, being age 40 or older, and ethnicity (African-Americans, Pacific-Islanders and Hispanics). Also, sleep apnea seems to run in some families, suggesting a possible genetic basis.