Sleep deprivation is a significant problem for patients in critical care units. Sleep is a complex, active process that is divided into 4 stages of non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep. Noise, lights, discomfort, pain, medications, and stress all contribute to a patient's inability to sleep. Lack of knowledge about the sleep stages, nursing routines, and frequent nursing assessment and interventions also impact the critically ill patient's ability to sleep. Education about sleep deprivation needs to be integrated into critical care courses and orientation programs. Sleep deprivation should be addressed on the multidisciplinary care plan and in health team conference, and nursing care planned accordingly. Sleep medications and their effects should be evaluated for each patient, as well as identifying medications that might be preventing or disturbing sleep.