Studies from as early as 2002 concluded that a person’s short sleep duration affects how long they live. Recent studies have demonstrated the importance of maintaining the recommended amount of sleep per night.
Research shows that your brain and body can’t adjust to less sleep.
You may feel sleepier after a few nights of poor sleep. After weeks or months of sleep deprivation, daytime drowsiness may normalize, but this doesn’t indicate your body is responding.
Persistent sleep deprivation impairs daily decision-making, memory, focus, and creativity. Insufficient sleep can damage metabolism, the cardiovascular system, the immune system, hormone production, and mental health.
Thus, even if you are becoming used to sleeping too little, your body may be developing more serious health issues due to lack of sleep. (Sleep Foundation)