Substance use disorder occurs when a person needs alcohol or another substance (drug) to function normally. Abruptly stopping the substance leads to withdrawal symptoms. Addiction means that a person has a strong urge to use the substance and cannot stop, even if they want to.
So it is important to maintain positive nitrogen balance in the body while sleeping. When you do and conditions are right so that your rate of protein synthesis exceeds your rate of degradation, and you maintain a positive nitrogen balance, you can grow while you sleep.
Research also suggests that a chemical called adenosine builds up in our blood while we are awake and causes drowsiness. This chemical gradually breaks down while we sleep. During sleep, we usually pass through five phases of sleep: stages 1, 2, 3, 4, and REM (rapid eye movement) sleep. These stages progress in a cycle from stage 1 to REM sleep, then the cycle starts over again with stage 1 (see figure 1 ).