Poor Sleep affects health in many ways. Lack of sleep can lead to injuries and accidents. It affects learning and thinking as well as it can result in memory loss. Sleep can adversely affect our metabolism and can lead to weight gain, impaired glucose tolerance, diabetes and heart attacks. Sleep deprivation cam put people at the risk of hypertension, stroke and it can even result in seizures. It can also kills the sex drive. Sleep deprivation has significant and important effects on the secretion of hormones of endocrine glands especially those follow a circadian rhythm. The classical example of this is effect of sleep loss in children and its impact on growth. Growth hormone is secreted during the slow wave sleep during the early part of night. When this sleep is disrupted the amount of growth hormone released is compromised and can result in growth retardation. Sleep deprivation can also affect the activity of thyroid gland. Thyroid gland has to work more during sleep loss as increased energy level is needed while staying awake. Sleep loss can even affect our immune function putting us at risk of frequent illnesses.