The term 'tolerance' in relation to drug use refers specifically to the phenomenon whereby a person's body becomes accustomed to a substance over time. As a result, an individual may find that they need to consume larger amounts of the drug to achieve the same effects they once experienced with smaller doses. This is particularly relevant in situations involving regular use of alcohol, cannabis, or other substances, where the user's body adapts to the presence of the drug.
Tolerance is a critical concept to understand because it can lead individuals to increase their consumption levels, potentially escalating their risk for overdose or adverse effects. In this context, while increased physical dependence and drug withdrawal symptoms are related to prolonged use, they are not the main definition of tolerance. Likewise, legal intoxication levels pertain to legal thresholds for driving or other activities rather than the biological adaptation to a substance. Thus, the correct understanding of tolerance centers around the increased dosage needs due to the body's adaptations to the drug.