CSSD Practice Exam 2025 – Complete Study Resource

High doses of caffeine are known to significantly stimulate the central nervous system, which can lead to increased heart rate and heightened feelings of anxiety. Caffeine functions as a stimulant, affecting neurotransmitters in the brain that regulate mood and arousal, which can elevate heart rate (HR) due to its stimulating effects on the cardiovascular system. Furthermore, excessive caffeine intake can lead to symptoms of anxiety, such as restlessness, nervousness, and insomnia. These physiological responses to caffeine consumption, especially in large amounts, demonstrate the potential for adverse effects on both mental and physical health, making this answer the most relevant concern associated with high caffeine consumption.

In contrast, decreased heart rate is not typically associated with high caffeine consumption, as caffeine tends to have the opposite effect, stimulating increased heart rate. Reduced muscle mass is unrelated to caffeine intake; while caffeine may have some effects on metabolism and energy utilization during exercise, it does not directly lead to muscle loss. Lastly, improved hydration is a common misconception, as caffeine can act as a diuretic at high doses, which may instead contribute to dehydration rather than enhancing hydration status.