Can drinking a lot of cokes and not enough water cause dehydration?

Unlikely. While the caffeine in the coke will make you pee more, it will not necessarily dehydrate you.People consume water value in a number of items other than straight water.Apple sauce, peaches,pears, etc are about 90% water,while most fresh vegetables are 60%.You could go all your life and never drink straight water & still keep up with your hydration status.
Not enough water. Coke and similar beverages have caffeine. Caffeine has diuretic effect making you urinate more. You could dehydrate if you drink too much coke and not enough water on a very hot day.

Related Questions

What can I do at home to prevent dehydration? I drink water, coke, tea all day. What r early symptoms? Been severly dehydrated 4x's.

Time for a visit. If you've been through it before you know the basics.Dry mouth, headaches, dizziness on standing, etc.If this is something recurrent for you it's time wright down all you can remember about how this started & schedule a visit with your doc. People can acquire a loss in the ability to maintain hydration through the complex interplay of kidneys & hormones. Testing may sort out the problem & help fix it. Read more...