We’ve all encountered a health record before. When we go to the doctor, it’s usually the crusty-looking cardboard file that the assistant removes from a cabinet, which the doctor stares at as she tries to remember who you are. And ‘who you are’ for the doctor is not necessarily the same as who you think you are. For the doctor, who sees you for about 10 to 15 minutes and writes mysterious notes as you try to remember for exactly how long you’ve been feeling this way, diagnosis is not as exact a science as it could be.

Imagine if you held that file – on your cellphone, PDA or computer – and could input data in real time about what you’re eating, how you’re feeling, how much exercise you’re doing. This is probably not that critical when you have a cold, but when you have a chronic condition like diabetes or breast cancer, these details are significant.