Excessive caffeine consumption can lead to a variety of side effects, some of which are quite impactful. Common effects include restlessness, anxiety, and insomnia. Individuals may also experience digestive issues, such as stomach upset or acid reflux. High caffeine intake can result in increased heart rate and blood pressure, leading to potential cardiovascular complications. In some cases, very high consumption can lead to symptoms like jitteriness or even panic attacks. Moreover, sudden cessation of caffeine can lead to withdrawal symptoms like headaches and fatigue, signifying the importance of moderation in intake.