A sign is something other people, like a doctor, notice while a symptom is something that the patient describes. For example, drowsiness could be an indicator, but enlarged pupils are clues.
Drug Addiction - an addicted person cannot resist or restrict himself to the intake of the substance be it drug, alcohol, cigarette. He/she continues to use it, despite the fact that it may be harmful (the person may or may not be aware of the possible risk).
Drug addiction makes the body have a strong desire for the substance. Addicts may desire to quit (give up), however experiences it very hard to do without assistance.
The signs and symptoms of substance reliance change as indicated by the individual, the substance they are dependent on, their family history (hereditary qualities) and individual conditions.
Some signs and symptoms of abuse could be:
Certain alcohol or substance abusers who aren't technically addicted might also be affected by or cause a few of the above-mentioned descriptions, though these abusers don't generally experience the withdrawal symptoms of addicts or the exact same obsession to use the substance.