Insomnia, which is Latin for "no sleep," is the inability to fall asleep or remain asleep. Insomnia is also used to describe the condition of waking up not feeling restored or refreshed. According to Dr. Mark Mahowald, Professor of Neurology at the University of Minnesota Medical School and Director of the Minnesota Regional Sleep Disorders Center at Hennepin County Medical Center, insomnia refers to the inability to get the amount of sleep you as an individual need to wake up feeling rested