A: Caffeine's diuretic properties will make you lose water, which makes dehydration from caffeine particularly common.

Dehydration can lead to some uncomfortable side effects, including headaches and constipation. If you're not careful and moderate your intake, it can negatively impact performance during physical activity.

The best way to avoid this is to drink at least two glasses of water for every cup of coffee or other caffeinated beverage. 

Read more about the benefits of Caffeine and Drinking Coffee here.