Bestselling author Robin Cook started his first novel when he was in the third grade.

"I only wrote it because I was disappointed with the fact that Stuart Little and Margalo never got together," he says. "When I was in the fifth, sixth and seventh grades, I had a favorite author and I loved his books, so I decided I was going to write one."

Cook didn't get very far with that one, either.

"I didn't know you had to have a story before you started," he says. "It started with a boy waking up and smelling bacon."

Despite those early attempts at fiction, Cook never intended to be an author. To this day, he considers himself a doctor first and foremost - one who happens to write.

An opthalmologist, Cook decided to turn his hand to fiction to educate the public.

"In my first book, I wrote about being an intern," he says. "I suddenly realized I had something to say that no one else was saying. That's what made me become a writer, the idea that somebody should be saying this."

While he found a publisher for "The Year of the Intern," the book wasn't as successful as he'd hoped it would be.

"At first, I thought it would be interesting to write books about medicine that were correct rather than the fodder everyone seemed to want," he says.

"All the books I'd read and the shows I'd seen were all wrong. There was room for something else. That was the real motivation."

With his second novel, Cook set the publishing world on its head by inventing the medical thriller. "Coma" scared the heck out of everyone who read it and was a wildly successful bestseller that was made into a movie that also was wildly successful.

"I remember back then one of the things that bothered me so much was that the public had accepted what it had seen in television movies and novels: That if you get sick, medicine is going to get you well," Cook says. "I realized how many screw-ups happened, which hasn't really changed all that much.

"I was the first one to tell people what could happen," he says. "'Coma' scared everybody, and I thought if people were scared, they wouldn't be such fodder.

"I remember people saying, 'I'm so tired, I think I'm going to check myself into a hospital,'" Cook says. "I would say, 'No, that's the last thing you want to do.'"

With the success of "Coma," Cook realized that for a novel to be a bestseller, it must be fun to read.

"But books are not fun to write," he says. "That is a deception. Writing is not an easy phenomenon. There always seems to be something else I should do before I sit down to write.

"I was lucky enough to get drafted into the military," Cook says. "That was the beginning, the first time I had free time to write."

Drafted into the Navy, Cook served as an aquanaut. He spent a tour of duty in the South Pacific on a submarine before being transferred to the Deep Submarine Systems Project.

"I think everyone is scared by the fact of our mortality," Cook says. "Doctors, more than anyone else, know we're sort of living on the precipice. Any time I write about this stuff, it scares me, too."

Cook's other books include "Outbreak," "Mindbend," "Mutation," "Harmful Intent," "Vital Signs," "Blindsight," "Terminal" - the list goes on and on.

"Had I been doing this 50 years earlier, I probably would have run out of stuff," Cook says. "Now with the pace of change, in particular technological change, there's always something new to write about."

In his latest book, "Cell," Cook is treading new waters.

"When people look at the book and see it's a Robin Cook book, they'll think it's about stem cells," he says. "No, the title refers to the cellphone.

"It's talking about digital medicine and the revolution that's coming," Cook says. "'Coma" turned out to be an iconic book because it was the first book that talked about the dark side of medicine. It opened up people's eyes. This book does the same thing."

"Cell" will likely surprise readers.

"We're facing a digital revolution in medicine," Cook says. "It's amazing to me how few people are aware of what's coming and how fast it's going to come."

Health care as it is today should be called sick care, Cook says.

"We talk a little about prevention, but it's never been center stage," he says. "Most people don't want it. The responsibility of eating properly, exercising, sleeping, not smoking - most people don't seem to follow those very easy things.

"With the digitalization of medicine, medicine is going to change its paradigm. It's going to become much more about preventative care.

"It's also going to become very democratic in that you are going to be in charge of your own health care," Cook says. "Your doctor or hospital has all your records and don't want to share now, but right around the corner, you're going to be the sole possessor of your own medical info."

The smartphone will become a lifeline.

"Your cellphone will be your doctor, not just to monitor your temperature or heart rate, which it is going to do; in fact, it's going to do it constantly," Cook says. "You're going to have a doctor in your pocket and it's going to work unbelievably well."

In his book, Cook finds the dark side in all this. After all, it is a medical thriller. But he's excited about the imminent revolution.

"I think people are going to be amazed - a lot of doctors too," Cook says. "Your doctor is not going to be like a priest in the middle ages any more.

"You are going to go to the doctor and tell the doctor what to do. The other way it's going to change things is by being connected to a supercomputer is going to make genomics work.

"All medicine today treats you as a group, but now you will be treated as an individual," he says. "Instead of being given a medicine that might help, your genome is going to determine if the medicine is going to help instead of giving you side effects."

The idea for "Cell" came in the middle of the night.

"I woke up at 3 a.m. with a sudden understanding of what is going to happen," Cook says. "Medicine is going to completely change, and most people are so unaware. I thought, 'I'd better write this book because somebody else is going to.'

"When I was writing 'Coma,' I was worried someone else would write the book and take the shock value away," he says. "Before 'Coma,' medical books and shows were all like 'Marcus Welby, M.D.' After 'Coma,' they show a lot of weird people in medicine."

Not surprisingly, not all doctors approve of Cook's subjects.

"I remember getting heat from a couple of surgeons, who said I was scaring people away from getting elective surgery," he says. "But there's a reason doctors are not all excited about getting elective surgery on ourselves."

As he is still practicing medicine, Cook doesn't have unlimited time to write.

"When I'm actually writing a novel, I usually do it in a very concentrated period of time," he says. "I'm juggling a bunch of stuff in the air and I've got to keep going.

"If I stop even for a few days, it's hard to get back to where I was," Cook says. "When I'm writing a book, I usually stay with it."

He says his main goal is to keep people awake, and sometimes he succeeds too well.

"There are a lot of writers out there who write about serial killers," he says. "If we had as many serial killers as writers, we'd be in trouble, but it's not something that affects people's daily lives.

"But we're all a part of having to go to the hospital and doctors. We all experience being irritated by waiting in the office; we've all been a little afraid of going to the hospital, all afraid of getting a flu shot.

"You can read a thriller about a big, white shark and say, 'I'm not going into the ocean,'" Cook says. "But you can't read one of my books and say you're not going to the doctor. We're all in the same boat, even us doctors."