Caffeine is the world's most widely consumed psychoactive drug, lauded for its energy-boosting and focus-enhancing effects.

Caffeine is safe in moderate amounts, but excessive intake, especially from supplements or in children, can pose serious ...

Caffeine affects the body in a variety of ways, particularly if you drink a lot. Having too much can cause gastrointestinal ...

Caffeine shifts brain activity during sleep by increasing EEG complexity and reducing long-range temporal correlations, ...

Caffeine is also a diuretic, which means that it can dehydrate your body. People who drink nothing but highly caffeinated drinks can end up in the hospital after passing out due to severe dehydration.

Our stories are reviewed by medical professionals to ensure you get the most accurate and useful information about your health and wellness. For more information, visit our medical review board.

If you suddenly stop or reduce your caffeine intake after consuming it regularly — typically more than 200 mg per day for more than 2 weeks — you may feel the symptoms of caffeine withdrawal.