Does coffee dehydrate you?

I just read up on this myself. According to the Mayo clinic, coffee or caffeinated drinks will only dehydrate you (through a diuretic effect ) if you drink upwards of 5-7 cups of them a day. So a couple cups of coffee will not dehydrate you. I personally have one cup of coffee every day, to start my day, followed by 2 liters of water throughout the rest of the day. Occasionally I have an iced tea in the afternoon, as well. So drink up.

I do not have time today to do extensive research on the subject. Any thoughts?

I normally drink 2-3 cups a morning. Coffee is the first thing on my mind in the morning and it is the first thing I drink/eat. Should I be drinking water first?

It is considered a natural diuretic, however, when my mom was on Hospice care, the nurse told her that coffee also helps to keep you "regular". So, I think they "cancel" each other out. Just my thoughts.