After decades as a technological laggard, medicine has entered its data age. Mobile technologies, sensors, genome sequencing, and advances in analytic software now make it possible to capture vast amounts of information about our individual makeup and the environment around us.

The sum of this information could transform medicine, turning a field aimed at treating the average patient into one that’s customised to each person while shifting more control and responsibility from doctors to patients.

The question is: can big data make health care better? “There is a lot of data being gathered. That’s not enough,” says Ed Martin, interim director of the Information Services Unit at the University of California San Francisco School of Medicine.

Today many companies and health-care providers are adding other layers of information to create an increasingly precise, patient-specific brand of medicine.

New mobile technologies, for example, could provide information about a patient’s everyday behaviours and health, creating opportunities for care providers to influence patients far more frequently.

Data brought in from electronic health records would add doctors’ insights, test results, and medical history. Genetic data would offer insight into whether patients are predisposed to certain conditions or how they might react to treatments.

In development are even more advanced devices capable of continuously monitoring such key metrics as blood oxygen, glucose levels, and even stress. And companies like Apple are hoping to become repositories for all this information, giving consumers new ways to track and perhaps improve their health.

This kind of information may be useful and interesting for anyone, but it can become essential for the millions living with chronic conditions like diabetes, heart disease, and depression. WellDoc makes a prescription-only FDA-approved “patient coaching” system, which advises users on how much insulin they should take in light of information recorded on their smartphones: blood sugar levels, recent meals, and exercise.

Ginger.io uses data collected (with permission) from a phone and other sensors to assess the behaviour of people with mental illnesses such as depression. Are they calling loved ones, or getting enough sleep? Over time, both companies will aggregate this information to help doctors study and improve treatment overall.

“It’s like one of the largest clinical trials in history,” says Chris Bergstrom, WellDoc’s chief strategy and commercial officer.

Families affected by Phelan-McDermid syndrome, a rare condition in which a deletion on chromosome 22 causes problems such as learning and memory deficits, are building a database of information from genomic tests, clinical medical records, extensive family surveys and histories, and more.

The goal is to create a central repository where researchers can examine multiple sources of data simultaneously. That’s increasingly important as researchers begin to see connections between Phelan-McDermid, autism, and other conditions.

Another benefit: data that once would have been locked up in one academic researcher’s lab will now be readily available to many different experts.