Tolerance and dependence People who drink heavily usually develop a tolerance to alcohol. They need to drink more to experience the same effect. As a result some people can drink large amounts of alcohol without appearing drunk. However, the amount of alcohol consumed can still damage their health. People who regularly drink heavily may become dependent on alcohol.
Dependence can be psychological or physical, or both.
People who are psychologically dependent on alcohol find that drinking becomes far more important than other activities in their life. Physical dependence occurs when a person's body adapts to alcohol. The body gets used to functioning with alcohol present. If a physically dependent person suddenly stops drinking they will have withdrawal symptoms because their body has to readjust to functioning without alcohol. Symptoms include loss of appetite, nausea, anxiety, inability to sleep, irritability, confusion, tremors and sweating.