Some start-ups are using social and mobile technology to give consumers more control over their health.
Azumio: Offers an app for iPhones and Android devices that can measure your heart rate by using the phone's camera to measure blood flow through your fingertip.
Castlight: Comparison shopping for health plans.
CellScope: Makes an attachment for smartphones that lets parents e-mail a photo of their child's ear canal to a pediatrician, saving a trip to the doctor's office to diagnose an ear infection.
Doximity: Smartphone messaging app that lets physicians communicate with each other and find referrals for patients.
Fitbit: Helps users keep track of how much they're walking and how many calories they're burning, via a clip-on motion sensor.
GravityEight: Internet platform to let users track their sense of well-being, measured by factors such as exercise and sleep.
Massive Health: Stealth start-up that's using mobile technology to help people with chronic conditions like diabetes manage their health.
