Doctors tap the potential of smart watches, using them to monitor patients' health and progress

More than 200 million people worldwide are wearing smart watches. But your Fitbit and Apple Watch can do so much more than relay your messages, play music or track your steps. Your smart watch may be smarter than you think.

Whether it's too fast or too slow, when a heartbeat is off beat, it may mean trouble.

"Patients that develop atrial fibrillation can have pretty severe consequences, specifically as it relates to stroke," said Dr. Matthew McKillip, an electrophysiologist.

But he said you may already be using one of the newest tools in the fight against A-Fib, your smart watch.

"Patients now have the ability of recording arrhythmias in real time," he said.

A Stanford study of 400 thousand people found Apple watches were able to correctly identify 84% of cases of A-fib. A smart watch also helps doctors monitor patients pre and post operation.

"Which will track step counts, stride length, heart rate and a variety of other data points that we don't normally track as a surgeon," said Orthopedic Surgeon Dr. Jeffrey Declaire

Declaire is part of an Apple Watch study that gives him daily real time data on his patients before and after knee replacements.

"A month before surgery, they started sending me educational information as well as exercises to do, and they track how you're doing with your exercises," said knee patient Denise Erhart.

And people with diabetes like Sydnie Stephens-Boussard can monitor glucose levels without that dreaded pin prick.

"So, when I'm going too high, my watch will ding. And then when I'm going too low, it'll also ding," she said.

And other studies suggest wearable devices might also be able to detect other illnesses like the common cold, the flu, even Lyme disease.

"This is actually something that is in my own practice directly impacting care," said McKillop.

Smart watches are also becoming popular to monitor elderly family members as most have detection technology that will call 911 if they take a fall.

Now that the tech is being used, McKillop says more focus will need to be done on ways to make the health information secure and privacy compliant throughout the healthcare industry.