A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function.There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.
In pharmacology, a drug is "a chemical substance used in the treatment, cure, prevention, or diagnosis of disease or used to otherwise enhance physical or mental well-being.Drugs may be prescribed for a limited duration, or on a regular basis for chronic disorders.
Recreational drugs are chemical substances that affect the central nervous system, such as opioids or hallucinogens. They may be used for perceived beneficial effects on perception, consciousness, personality, and behavior.Some drugs can cause addiction and/or habituation.
