The world population is going through under the tremendous pressure of COVID 19 pandemic. In second and third wave of widespread of corona virus most of the countries announced second or third lockdown. These lockdown creates detrimental effect on physical and mental health of common people. This paper is related with sleep, sleep disorder or insomnia and its effect on physical and mental health of common people. There has always been a curiosity to know and understand all about the sleep. In this research, we have tried to find out the mystery of sleep and its effect on physical and mental health. Sleep is related to our mind and brain. Good and adequate sleep is very important for everyone. The disorder related with inadequate and improper sleep known as insomnia. Insomnia is one of the major problems that human being is facing now days. Sleep disorder or insomnia having serious impact on physical and mental health. In last we have tried to suggest some remedial actions also.

Keywords : Sleep, Mind, Brain, Insomnia, Anxiety, Depression, Deprivation, NREM, REM.