A large percent of truck drivers are at risk for Obstructive Sleep Apnea (OSA). OSA occurs when there are periods of complete or partial blockage of the upper airway during sleep. Those at the greatest risk for OSA are men and postmenopausal women, older than 42, who have a Body Mass Index (BMI) of 35 or above, a family history of OSA, and/or a small jaw or airway. OSA can increase potential for high blood pressure, heart attack, and stroke if left untreated. Most importantly for the trucking industry, OSA leads to excessive sleepiness and exhaustion.