Caffeine Caffeine Caffeine, the most widely used drug in the world, is a stimulant.
Caffeine is a physically addictive drug .
Like all stimulants, caffeine raises blood pressure and increases the user's risk for high blood pressure, heart disease and other health problems. Its effects range from mild alertness to heightened anxiety and body tension. Some regular users who stop using consuming caffeine may experience withdrawal symptoms including drowsiness, headaches, irritability, nausea and vomiting and depression.