About author : Suvarna*, Dr. Hindustan Abdul Ahad B. Pharmacy, Balaji College of Pharmacy, Anantapur, AP, India E-mail: suvarnabcp@gmail.com INTRODUCTION: Sleep is a naturally recurring state of relatively suspended sensory and motor activity, characterized by total or partial unconsciousness and the inactivity of nearly all voluntary muscles. KEY WORDS: sleep, stages, circadian clock STAGES OF SLEEP: Rapid eye movement ... Read More »