There are patients – and then there are active patients. And some of the people I talked to for my book I’d call very active patients. They have struck out on their own and made radical decisions about their healthcare.

Teri Smieja is one of these heroes. When she learned that she had a genetic risk for breast and ovarian cancer, she embarked on a series of decisions – illustrated beautifully in this excerpt in Wired Magazine – that resulted in her getting two preemptive surgeries.

Todd Small is another. A 40-something Seattle father who happens to have multiple sclerosis, Todd first came to my attention when I reported a story about Patientslikeme.com for the New York Times Magazine. At the time, Todd was actively engaged in his medication – he learned from his fellow PatientsLikeMe community members that his dosage for a drug called baclofen was probably too low, and adjusted it accordingly (working with his doctor, I hasten to add).

When I checked back in with Todd recently while reporting the book, I was surprised to hear that he was about to embark on an even more radical decision: he had heard about an experimental stem cell treatment for MS, and was about to give it a whirl. Todd, who admits he’s no whiz at science, couldn’t make out what the research was saying. So he turned to the PatientsLikeMe community. “If somebody could decode this into simple layman’s terms, it would be much appreciated,” he posted in an online forum.

Soon enough, his fellow members did decode the research – and the consensus seemed to indicate that the procedure, though somewhat risky, was a reasonable bet. It was nothing to sniff at: the treatment begins by extracting 400 milliliters—a little more than a can of soda—of bone marrow from the leg. For several weeks, those cells are used to grow more cells, after which the patient returns and about 50 million cells are injected into the spinal column.  The cells seem to repair some of the damaged myelin in the central nervous system, lessening the symptoms of MS. About 60 patients had been treated with the procedure, and 55 had reported major improvements in their symptoms, including a former Canadian golf pro who was able to return to the game.

To Todd, the idea “was a no-brainer,” he told me later. “I just gotta go for it. If I don’t do this, I’ll be kicking myself. And in another year, I’ll have to quit my job at the shop. I have a family. I have two kids. I owe it to them to at least try this.”

Such self-guided research unnerves the medical establishment. That way, they warn, quickly leads to quack cures and dangerous treatments. That’s no doubt true in many arenas. But the power of PatientsLikeMe is that its members take their science seriously. They demand published research, not anecdotes. They’re quick to debunk phony cures and quackery. They consider themselves not just beneficiaries of research, but participants in an ongoing research project.

PatientsLikeMe co-founder Jamie Heywood calls this “personalized research.” On a smartly run, well-organized Web site, patients can play a huge role in informing each other; they can decentralize and distribute information that once was available only through a personal physician. This means that people can share not only their stories but also best practices and results. The crowd can create its own research, becoming what Jamie describes as “an insight engine.”

The same spirit propels CureTogether, a Web site that lets people with dozens of conditions, from allergies to vulvar vestibulitis, track their treatments and symptoms. Like PatientsLikeMe, CureTogether has an insatiable appetite for tracking patient data, and a faith in collaborative insight. “It’s driven by the patients, not by scientists.” Carmichael calls the insights that result from the nearly 7,000 members at CureTogether “collective wisdom.”

PatientsLikeMe and CureTogether can be seen as a direct challenge to physicians’ omniscience: The companies not only let members track their disease progression, they tacitly encourages them to try to turn those progression curves in a positive direction. This is what’s unnerving to many doctors. But it’s also what makes the self-guided approach so compelling. When it’s done with data, when it’s done as a feedback loop, it can actually result in good, more informed decisions.

Not all of these approaches are right for everyone. Constant self-tracking of the sort that PatientsLikeMe requires—updating one’s symptoms and dosages and progress—can be tedious, especially for somebody who already has a chronic illness. And not everyone is the “early adopter” type. But the truth is, you don’t have to be an early adopter to understand the virtues of mindfulness. At their best, Web sites like PatientsLikeMe and CureTogether offer a true middle path—one that has a grounding in science, yes, but also an understanding that we ordinary folk tend to look to each other, rather than textbooks or research papers, for advice on how to lead and improve our lives. The stories we share about our lives, especially stories about our health, can be incredibly powerful.

The key is to combine our affinity for stories and narrative with our capacity for rational decision making. It’s in the combination where there’s relevance, and where there’s relevance, there’s an occasion for action.