“I love sleep. My life has the tendency to fall apart when I’m awake, you know?” —Ernest Hemingway. Sleep is an essential part of life. Even the world renowned writer, Ernest Hemingway, trusted sleep to heal everything. Sleep is the remedy to a lot of ailments. From headaches to heartbreaks, trust sleep to be the ultimate mood lifter.Drudging in our busy lives, we often choose to give the recommended eight hours of sleep a miss. In our quest for money, fame and success, we often ignore our health. Sleep deprivation has long term effects on both mental and physical health. Apart from making one feel grumpy and tired, lack of sleep can reduce lifespan. A sleep cycle consists of five stages that involve four non-REM (Rapid Eye Movement) stages and one REM stage. Progressing from stage one to the REM stage makes one complete sleep cycle. Incompletion of the sleep cycle may result in sleep disor-ders. Migraine, Alzheimer’s and even inferior reflexes may be the drawbacks of not reaching the REM stage of the sleep cycle.Two biological processes regulate sleep. They are the homeo-static process and the circadian process. These two mechanisms are influenced by genes. External determinants, such as drugs, food habits and timings, stress, schedules, naps and so on, also impact the sleep-wake cycle, either directly or indirectly. The circadian rhythm and the sleep-wake homeostasis balance each other. If disturbed, these two processes may lead to sleep related sicknesses. People with circadian sleep disorder experience odd sleep-wake cycles. They face difficulty in staying awake during the day that includes normal office or school hours. The circadian rhythm controls body temperatures and secretion of hormones that control sleep timings. Sleeping at odd hours of the day, difficulty in staying awake in the morning or evening and changing sleep timings, are symptoms of the circadian sleep disorder.Why is sleep so important?A good night’s sleep can restore your bodily functions to normal. It has an impact on your cognitive performances, thermoregu-lation and preservation of energy and also on resurgence of tissues. It also improves your memory and maximizes your retention capability. Therefore, you would experience greater productivity and improvement in concentration levels. It also regulates glucose metabolism and brings about a significant reduction in the risk of type-2 diabetes. Less hours of sleep can cause havoc in the central nervous system. The central nervous system controls the body and it being affected may lead to respiratory diseases, heart diseases, digestive disorders and so on. Fatigue, paranoia, anxiety and depression could become your everyday issues. You could experience micro-sleeps during office hours. As a result, you would become less productive. During microsleeps, the brain shuts down on its own, making the person experiencing it mentally asleep during work. Often, this leads to distorted perceptions of reality and dreams.More often than not, despair and mood swings are caused due to sleepless nights. It becomes stressful to concentrate. You become unmindful in a short span of time. Fatigue is one of the main reasons behind road accidents. The 1986 Chernobyl nuclear disaster was a consequence of sleep deprivation.Lack of sleep can take a toll on your immune system. It makes you susceptible to coughs, colds and flu during seasonal changes. It is possible that you may gain weight due to sleep disorders. It affects the leptin and ghrelin hormones. It reduces levels of leptin, the hunger inhibiting hormone and increases that of ghrelin. Ghrelin boosts your hunger pangs, making you eat more during late nights.Apart from physical well-being, poor sleeping habits can also cause psychological complications. Hallucinations, paranoia, depression are the long term effects of sleep loss Sleep deprivation can trigger sleep paralysis, a condition where the body feels paralysed while the brain remain conscious either during awakening or while falling asleep. During such periods, people experience hallucinations, often mistaking them as paranormal activities.Depriving yourself of sleep could increase blood pressure and aggravate chances of stroke and dementia. There could be impairment of cognitive processes. A sleep deprived person may demonstrate clumsiness, garbled speech, inability to remember names and may even be unable to complete sentences.Energy drinks and caffeine may aid you in the process initially but in the long run, it may disrupt sleep patterns and though medication can help you out with such complications, the best way to fight sleep deprivation is to get more sleep.