Medical Daily interviews Dr Andrew J. Westwood, assistant professor of Clinical Neurology Division of Epilepsy and Sleep Disorder at Columbia University Medical Center in New York City.

“If you can function during the day, then you’re getting enough sleep,” Westwood said. “The average person needs usually between seven and eight hours of sleep, but everyone is different. If you feel fine and can function well during the day on three hours of sleep, then you don’t need to worry.”