What is a common clinical manifestation of caffeine abuse?

A common clinical manifestation of caffeine abuse is increased diuresis. Caffeine acts as a natural diuretic, meaning it promotes the production of urine by the kidneys. This effect occurs because caffeine inhibits the reabsorption of sodium and water in the renal tubules, leading to an increase in urine output. As a result, individuals who consume excessive amounts of caffeine may notice more frequent trips to the bathroom.

The other options, while related to different substances or conditions, do not accurately represent the typical effects of caffeine overdose. For instance, respiratory depression is more commonly associated with depressants like opioids rather than stimulants like caffeine. Similarly, severe hallucinations are not a typical response to caffeine; rather, they may occur due to the abuse of certain hallucinogenic drugs. Lastly, relaxation and sedation are generally contrary to the stimulating effects of caffeine, which can lead to increased alertness and anxiety rather than a calming effect.