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Why might a person need larger doses of a drug after repeated use?

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drug use The use of psychoactive drugs, such as pain medications or illegal substances, often results in emotional, physical, and social harm.

A person may require larger doses of a drug after repeated use due to a physiological phenomenon known as tolerance.12

Tolerance occurs when the body, particularly the nervous system, adapts to ongoing exposure to a substance. At a cellular level, this adaptation results in a diminishing response to the drug, meaning that the same amount of the substance no longer produces the original effect.21

As tolerance develops, the duration of a drug's effects often shrinks, leading an individual to take the substance more frequently or in increasingly larger amounts to achieve the desired result. While this process is a cardinal characteristic of many types of addiction, it is a distinct physiological process that can occur independently of physical dependence. Because the body has adjusted to the presence of the drug, higher concentrations are necessary to overcome this cellular adaptation and regain the drug's initial impact.12