<unk>  means that a person needs a<unk>  to function normally. Abruptly stopping the<unk>  leads to withdrawal symptoms.<unk>  addiction is the compulsive use of a substance, despite its negative or dangerous effects.
A person may have a physical<unk>  on a substance without having an addiction. For example, certain blood pressure medications do not cause addiction but they can cause physical<unk> . Other<unk> s, such as cocaine, cause addiction without leading to physical<unk> .
Tolerance to a<unk>  (needing a higher dose to attain the same effect) is usually part of addiction.
Drug dependence
Drug addiction
Cocaine dependence
Opioid abuse and dependence
Alcohol dependence
Alcohol withdrawal
Nicotine addiction
Hospitalism