Editor's Note: This article is part of Inc.'s 2014 Best Industries package. Read on, for more on the top industries for starting a business now.

Most professionals carry a cellphone on them all day, and doctors are no exception. Today it's possible to take smart phones, snap on a small piece of hardware, and transform them into medical devices.  

"I called them ADD-apters," says Eric Topol, MD, a cardiologist and author of The Creative Destruction of Medicine. He tests such add-ons at Scripps Clinic in San Diego where he practices. He's even been seen on TV using one of them to check comedian Stephen Colbert's eardrum injury. 

That device, called the CellScope Oto, is a magnifying lens attachment that works with the iPhone's built-in camera to capture images of a patient's eardrum and ear canal. Having pilot tested it at the clinic, Topol says he is happy to report that it works great. 

Yet Topol isn't the only physician combining mobile technology and medicine. The mobile health industry, or "mHealth" as it's called, is growing at a head-spinning clip and quickly rising as a top industry for startups. Between girding for the Affordable Care Act and simply keeping up with the technology Jones, the market for mHealth products and services could grow tenfold and surpass $10 billion by 2018. 

Awash With Opportunity

The increasing adoption of mobile devices by doctors and patients has touched almost every area of health care. The transition stage that the industry now finds itself in is largely driven by the fact that both patients and providers have come to expect that technology should create the same ease and efficiency in health care as it already has in other industries. 

"I call it the biggest turning point, inflection in medicine," says Topol. "And it's still in the very nascent, early stages."

But the real potential of devices like CellScope Oto, which isn't yet for sale, will be realized when it's in a consumer's hands, not a doctor's. For example, parents could use CellScope's Oto to capture images of their child's ear infection. 

They can then use the phone to send those images to a pediatrician and, in some cases, get a diagnosis, eliminating the need for a doctor's visit. Devices like these led Topol to believe that the smartphone will be the greatest conduit of patient health data that the medical field has never had.  

Also on the mHealth bandwagon is Axial Exchange, a health care software developer in Raleigh, North Carolina. The company created a system that involves a patient-facing app and a provider-facing app. Upon leaving the hospital, patients can use Axial to access information about their disease or condition. The app also includes medication adherence and symptom tracking tools, as well as access to patients' medical records. 

Hospital specialists have a dashboard on their end, which helps to monitor patient progress. They can also share medical information with the patient's primary care doctor. Essentially Axial allows a patient's health information to go where they go -- whether it's the to the hospital, home or their regular doctor's office. 

The company, which was founded in 2009, has more than 70 hospital clients, according to the company's website. Perhaps Axial's greatest strength is that it has managed to get several sources of data to communicate with one another. 

High Hurdles 

Topol adds that entrepreneurs new to the health care space would be surprised to learn just how difficult that is, given that health care data live in disparate systems for the most part. "These things roll on their own. Everything is pretty much siloed," he says.

What's more, there may be significant regulatory obstacles to overcome for companies looking to enter the mHealth world. For instance, a major innovation barrier to entrepreneurs is their fear of scrutiny from the US Food and Drug Administration, says Chris Wasden, managing director of consultancy PricewaterhouseCoopers' Healthcare Strategy and Innovation Practice. 

To avoid attracting attention from the agency, some deliberately create a product that doesn't fall into FDA-regulated territory. "What that means almost by definition is that you're going to make a bad solution," Wasden said. 

"Ignore the fact that the FDA is going to perhaps be into what you're doing--for now," he said. "Focus on designing the solution that's really good and really effective. And then if you have a really good solution, don't be afraid to take it through a regulatory approval process." 

Some of the most futuristic-sounding mobile health products have already earned FDA-approval. For example, Proteus Digital Health developed a tiny ingestible sensor--about the size of a grain of sand--for medication adherence monitoring. Once a patient ingests his medication, the sensor communicates with a wearable patch that then alerts the patient's family and caregivers via an app. 

Proteus, however, didn't experience a quick and easy road to validation. The company began working with the FDA toward approval in 2008, and the agency didn't clear the ingestible sensor until four years later.  

Blue Skies Ahead

Still, as the government and employers look to rein in the still high cost of health care there's going to be a vast need for companies that can meet America's medical needs more efficiently. 

PlushCare is a startup that aims to do just that. As a response to the trend that asks employees to take on more responsibility over their health care purchases, the company helps prevent unnecessary doctors' visits.  

The company now offers individual subscriptions for rates that vary from $80 to $120 a year. The plans allow patients to access a doctor via videoconferencing and email. The service is currently only available in California. 

Ryan McQuaid co-founded the company in January after working at AT&T for years to help launch its mHealth platform. Through that service, patients can aggregate their health care data even if it stems from different sources. McQuaid, who had already run a startup before, was lured away from his day job partly by the idea of having the freedom to work quickly and experimentally. 

That notion is what McQuaid thinks is what will help startups stand out in this industry. "It's understandable that [giant companies like AT&T] don't want to put the entire business at risk for something that they're not sure if it's going to work out," says McQuaid. "I think that's why startups can be successful."