Thanks to an array of small devices and applications for smartphones that gather vital health information and store it electronically, consumers can take a more active role in managing their own care, often treating chronic illnesses — and preventing acute ones — without the direct aid of a physician.

A report in November by research2guidance estimated there were more than 17,000 mobile health applications designed for smartphones and that many were aimed at and being adopted by health care professionals. It forecast mobile and wireless health care services would expand significantly to reach 500 million mobile users, or about 30 percent of an estimated 1.4 billion smartphone subscribers worldwide, by 2015.

Examples of devices include a Wi-Fi-enabled cuff that can take your blood pressure and pulse and that connects to an iPhone to synchronize the data with records kept online, and blood glucose level readings can be sent by text message to a secure MyGlucoHealth portal, which provides instant advice to users on what to eat.

Microsoft’s HealthVault and Google Health also offer open platforms that allow people to store and manage their health information.