When someone stops taking crystal meth they often experience long periods of sleep and increased appetite because most users go on a "run", taking drugs for one or more days in a row and don't sleep or eat.
Tolerance is defined as the need for larger amounts of alcohol to become intoxicated.
The rate of alcohol absorption in the body depends on the concentration of the alcohol being consumed. For example, vodka is absorbed faster than beer, because vodka has a higher alcohol concentration.
In the most severe cases, untreated alcohol withdrawal syndrome can result in death.