Water needs depend on body size, activity level, climate and even the medications a person takes. Oscar Wong/Moment RF/Getty Images

One recent weekend, I didn’t drink much while out in the sun. That Monday morning, after seven hours of sleep, I still felt exhausted. I was irritable, moody and unfocused.

My first instinct was coffee, which only made me jittery. Then I realized I was dehydrated. I drank two bottles of water over the next hour — and felt like myself again. Hydration restored my body’s balance.

We hear so much about daily water requirements, and like you, I aim to drink mine carrying reusable water bottles in every shape, color and size. What you might not hear as much is that it’s not just water in — it’s water out.

Patients, even those with no kidney stone issues, a

See Full Page