The best indicator we currently have of becoming unwell is that familiar, off-colour feeling. Our senses aren't infallible, of course – goodness knows how many false alarms and unexpected illnesses we've all had – but it's the most reliable early warning system we've got.
Technology, however, may be about to change that. Lurking within imminent updates of the two main mobile operating systems, Apple's iOS and Google's Android, lie two software frameworks (Health Kit and Google Fit respectively) that have been described as "the beginning of a health revolution". They enable apps to collect, collate and exchange information about our state of health that could ultimately usher in a new era where our phones may know we are unwell before we do.
First came the fitness gadgets and smartbands. With the likes of Nike's Fuelband, Fitbit's Force and Jawbone's UP, wearable technology scored its first significant consumer hit; we became fascinated by the data generated by our movements and the information that could be inferred from that. A recent study by Flurry Analytics found that usage of fitness apps is growing some 87 per cent faster than the app market in general, as people embrace tools that can reaffirm or improve their fitness levels.
What's intriguing, however, is the emerging grey area between fitness data and what could be termed health data. While smart bands and associated apps tend to collate relatively benign information such as hours slept, miles walked, caffeine consumed or time spent brushing your teeth, there's provision within Health Kit and Google Fit for information we'd more normally associate with a visit to our GP: blood pressure, oxygen saturation, hydration levels, blood sugar levels and heart rate. "It's a step towards more medically orientated devices that lend themselves to capturing data that health professionals can act upon," says Dr Dushan Gunasekera, founder of myHealthCare, a private polyclinic based in Wandsworth.
That data, of course, has to come from somewhere. Health Kit and Google Fit are merely aggregators that facilitate the ingenuity of software and hardware developers – and that ingenuity is currently being funded by big increases in health-related venture capital.
iPhone-compatible oximeters and blood pressure cuffs are already sold via Apple's website. There's Dario, a "mobile diabetes management platform" that combines a smart meter to measure blood sugar levels with a smartphone app which interprets that data, along with other information you provide regarding carb intake and exercise. The smaller and cheaper these health sensors become, the easier it will be for data to be collated; for example, Google is currently working on a smart contact lens that could assess glucose levels in a more unobtrusive way then Dario's smart meter. "Wearable devices are already used in the NHS to measure blood pressure and heart tracings," says Dr Gunasekera. "So [Health Kit and Google Fit] could easily end up becoming accessible to primary care physicians."
Apple's Health Kit has received backing from the Mayo Clinic, a Minnesota-based medical research group that has tested a system of direct notifications whereby clinics could inform patients of unusual patterns in the data they've received. "The big vision is to switch from the old patient funnel where you feel sick, tell a friend, see a doctor, get tests, receive the results," says Ben Heubl from Zesty, a healthcare appointment booking service. "The new funnel is different: you track your results anyway – because the devices do it for you – and book an appointment online automatically."
It's hard to imagine Heubl's vision of an efficient, device-driven, paperless healthcare system implemented any time soon within an organisation as large as the NHS, but he's at pains to stress that this kind of data collation within a "patient passport" isn't new. "Patients Know Best is an electronic medical record (EMR) system which already links to NHS practices," he says, "and already has partnerships in place that cover wearable tracking devices."
Our enthusiasm for accessing EMRs has not been overwhelming thus far. Google Health, launched in 2008 as a central repository for health-related information, shut down in 2011 after failing to strike much of a chord. Microsoft's Health Vault, which launched slightly earlier, is still knocking around despite minimal attention, but now accepts information from a number of modern health apps and devices.
But the burgeoning interest in wearables looks set to breed a new-found curiosity in our health data that extends beyond the usual hardcore of health obsessives. "GPs already get people who print out reams of information from the internet and walk in having already incorrectly diagnosed themselves," says Dr Gunasekera. "And this wealth of data will create anxiety among some people. But when a patient comes in, it's useful to have a historic set of data and metrics; you're able to correlate things a lot quicker in the initial consultation.
That's good from a private perspective, but ultimately it could lead to time saving and efficiencies in the NHS, too. There will be challenges and hurdles, but it feels like the first step towards this elusive thing that everyone talks about: preventative medicine."
Apps, data readouts and automated alerts do not provide much in the way of bedside manner, and it's clear that the role of the doctor will be crucial within any streamlined, data-rich vision of the future of healthcare – although many GPs may still view these innovations with suspicion. "You're always going to get resistance to technology," says Dr Gunesekera. "When automatic blood pressure monitors were introduced a lot of GPs were unhappy about using them, and there will be concerns about accuracy. But the other main concern is confidentiality. It's crucial that medical data cannot leak in any way." Even though tech giants such as Apple and Google will be only too aware of the critical importance of data security, well-publicised cases of data leakage are bound to breed a lack of trust in any company that retains sensitive health information in digital form.
Having said that, we've continually demonstrated how flexible our attitudes towards privacy are when fascinating technology is dangled before us. And the eventual successors to fitness bands, whether they're externally worn or even implanted, have the potential to offer us the ultimate benefit: a healthier, longer life. Gentle warnings about our blood pressure may flash up on our phone's screen, much in the same way we currently receive a text message or a weather alert.
Initially, such messages might make us anxious and cause our blood pressure to rise even further. But in the longer term, we may view them as a welcome reassurance that our health is being efficiently looked after.