Withdrawal

Withdrawal is the response of the body to the discontinuance of an addictive substance. The symptoms can range from mild to severe and in extreme cases can be life threatening.
With all addictive substances, the body tolerates higher and higher doses and the therapeutic effect of the drug is lessened. However, the body's functions adjust themselves to the addition of the drug so that the addicted person may function more or less normally. However, once the addict ceases to use the drug, the body reacts adversely until it can once again adjust to the new situation, for example:
*It mistakes the lack of the drug for poisoning and rejects food, making the patient nauseous and inducing vomiting.
*It believes that the body temperature is too high and starts sweating to reduce it.
*Normal sleep cycles are disturbed, causing insomnia and fatigue.
All addictive substances cause withdrawal. The symptoms can be mild (caffeine withdrawal causes fatigue, nausea and headaches), to moderate (nicotine withdrawal causes anxiety) to severe (alcohol withdrawal, or the DTs, can cause hallucinations, anxiety, convulsions and death). Withdrawal can also result from the sudden cessation of therapeutic drugs such as tranquilizers or steroids.
Some drugs can be substituted for the addictive drugs, thus preventing the withdrawal symptoms. For example, methadone is a common substitute for heroin, and the nicotine patch contains the same drug as cigarettes without the side effects.