The health activity is organized with the necessary night work of nurses / technicians, doctors and other health professionals. Working night shifts is often associated with sleep deprivation and sleep difficulties. Sleep consists of REM and non-REM phases. Like most living organisms, there are clear daily or circadian biological rhythms in people. Sleep is also closely linked to immune functions. The paper describes and explains the physiology of sleep. It also lists some conditions that can occur in the event of a sleep disorder. The work of shift workers affects social and family life, since most leisure activities are related to afternoon and evening hours. Leisure activities are often associated with weekends, which are often work hours for the shift nurse / technician. An anonymous survey with 848 participants and 12 questions conducted online was explained in detail and graphically followed. The aim of the study was to examine the impact of night work on the health of nurses / technicians, and to examine whether nurses / technicians have difficulty sleeping, the immune system, and how they assess the stress of working alone at night. The results of the questionnaire negatively assess psychophysical abilities during night work. A greater problem with psychophysical abilities occurs after night work, with 85.4% of survey participants indicating worse psychophysical abilities than after a day shift. 59.3% of survey participants had difficulty falling asleep after night work. 79% of participants find that night work is more stressful than daytime work.