I'm following this crowd funded project with interest -
http://www.indiegogo.com/projects/scanadu-scout-the-first-medical-tricorder?c=home - although it's already received 5 times the funding it was originally looking for. With $500,000 already in the bank that should give its development a good chance at entering into the Qualcomm Tricorder X Prize for a bonus $10m.

This little device will allow you to quickly measure heart rate, body temperature, oxymetry, respiratory rate, blood pressure, ECG and stress - which can then be tracked easily on a smartphone app so that you can monitor any potentially dangerous changes.

As information is so important in diagnosis and prevention of long term illnesses, the more data the better. And with Watson already being trained to make medical diagnosis then in a few years it will be run of the mill to take a reading that gets uploaded to your cloud stored health profile which can be continuously monitoring for danger signs. If I received an alert to take some extra tests to check for problems, or to rule out them out, I'd certainly do it rather than wait for symptoms which may come too late.