WebMD's mobile app, an example of an app smartphone users might use for health information.

As of 2013, 95 million Americans are using mobile phones as health tools or to find health information, according to Manhattan Research. That's 27 percent more than 2012, when the number was 75 million.

These numbers come from Manhattan's annual Cybercitizen Health US survey. The research firm surveyed 8,605 US adults online and on the phone between August and September.

The study found that 45 percent of online adults with a chronic condition reported that the internet is essential to managing that condition. Manhattan listed the top ten conditions for which patients use mobile devices. Cystic fibrosis was number one, followed by growth hormone deficiencies, acne, ADD and ADHD, hepatitis C, migraines, Crohn's disease, chronic kidney disease, generalized anxiety disorder, and bipolar disorder.

Outside of just those with chronic conditions, 44 percent of online adults said the internet was essential for their health and medical decision making. Finally, 38 percent of smartphone users said their phone was essential for finding health and medical information.

Manhattan also asked people about where they used their mobile devices to access health information. The survey found that people used their smartphones at home as well as on the go, and that, for pharmaceutical companies, having an app was a strong influence on consumers.

These findings are not necessarily consistent with other research that's been done in these areas. In contrast to Manhattan's findings, for instance, the Pew Internet Project has found that chronic disease patients are actually less likely to use digital tools for health than their healthy counterparts. And a study by US Cellular this summer found that only 10 percent of their customers used their smartphone for health, in contrast to Manhattan's finding that 38 percent found the device essential.

Findings about the value of apps for pharma companies, however, were consistent with a recent report from Digitas Health, which found that patients who used mobile devices in the exam room were 80 percent more likely to switch to a different medication than those that didn’t, and twice as likely to request a specific medication.