A common side effect of consuming too much caffeine is insomnia. Caffeine acts as a stimulant, increasing alertness and energy levels. However, excessive intake can lead to restlessness, anxiety, and difficulties in falling or staying asleep. Other side effects may include increased heart rate, digestive issues, and headaches. For individuals sensitive to caffeine or those who consume it in large amounts, insomnia can significantly impact daily functioning, leading to fatigue and irritability. It's essential for consumers to monitor their caffeine intake to avoid these adverse effects, especially from caffeinated beverages like coffee, tea, and energy drinks.