But despite what you've heard, coffee and caffeinated tea are not dehydrating, experts say. It's true that caffeine is a mild diuretic, which means that it causes your kidneys to flush extra sodium and water from the body through urine.

Is tea good for dehydration?

Tea. Caffeine-free teas are great, especially if it's just an infusion of leaves in hot water. It doesn't matter whether it's herbal, black, green or chamomile; hot or cold—tea is just about as hydrating as water. Tea is also packed with antioxidants.

Does coffee tea really dehydrate you?

Drinking caffeine-containing beverages as part of a normal lifestyle doesn't cause fluid loss in excess of the volume ingested. While caffeinated drinks may have a mild diuretic effect — meaning that they may cause the need to urinate — they don't appear to increase the risk of dehydration.