Nearly half of all Americans have a sleep disorder, says sleep expert Lisa Endee.

“Americans think that not getting enough sleep is part of a normal culture,” Endee said. She is a Clinical Assistant Professor in the School of Health Technology and Management’s Respiratory Care and Polysomnographic Technology Programs at Stony Brook University’s sleep-testing center.

She said that the average adult should sleep between seven and nine hours per night, and a person who consistently sleeps less will develop “sleep debt,” which can accumulate to missing a whole night’s sleep.

“People who do not sleep enough feel tired and have slower reactions,” Endee said. “These effects multiply over several days of missed sleep.”

Slower reaction times increase the chances of being involved in a car accident. Fatigued driving directly causes more than 1,500 deaths from car crashes, according to the National Highway Traffic Safety Administration.

Sleep disorders are either the result of not getting enough sleep or not getting quality sleep. Some people can sleep 15 hours and still feel tired because they wake up constantly throughout the night.

And nearly nine million Americans use prescription sleep aids at least once a month, according to a recent study by the Centers for Disease Control. “Sleep aids are not a good solution at all,” Endee said. “People start to associate sleep with the pills, which prolongs the issue.”

“Not being able to fall asleep is usually a symptom of an underlying issue,” Endee continued. “People who are stressed, consume caffeine at night, and sleep with the television on are more likely to have trouble sleeping.”

Endee said that Americans should take the time to get proper sleep because it affects a variety of factors including metabolism and growth. “People need to be more aware of how important sleep is to their health,” Endee said.