>The child begins drinking a lot. It starts off with an excessive thirst. Can't go more than an hour without drinking. But ends up with them not being able to do anything, peeing constantly and never being able to quench their thirst.

Saw this first hand babysitting a kid a long time ago. He kept asking for glasses of water--almost begging for them while at the same time peeing frequently and then wetting the bed. Parents took him to the doctors and the diagnosis came swiftly.