We’ll riddle each post with plenty of statistics, polls, and other fact-finding information, as well as let you know where you can read further on many of the issues (such as here).

Over the last 40 years, the use of telemedicine has seen major growth, but it’s the last few years that have helped it spread rapidly. We’re now seeing full blown integrations into the ongoing operations of hospitals, specialty departments, home health agencies, private physician offices, and even consumer’s homes and workplaces.

This growth in telemedicine allows organizations like Doctors Without Borders to relay questions from physicians in underprivileged countries to its network of over 280 experts around the world, and back again via the internet and other telecoms.

So, how would one formally define telemedicine? It’s pretty simple:

Telemedicine is the exchange of medical information from one site to another via electronic communications to improve a patient’s clinical health status. Telemedicine includes a growing variety of applications and services using two-way video, email, smart phones, wireless tools and other forms of telecommunications technology.

Driven by quicker internet speeds, pervasive smartphones and ever-changing insurance standards, more health providers are turning to electronic communications to do their jobs—and it’s upending the delivery of healthcare.

For example, a growing number of doctors are linking up with patients by phone, email and webcam. They also practice consulting with each other electronically—sometimes even making split-second decisions on heart attacks and strokes. Patients, meanwhile, are using new devices to relay their blood pressure, heart rate and other vital signs to their doctors so they can manage chronic conditions at home.

Telemedicine also allows for better care in places where medical expertise is hard to come by.

As we mentioned, several times a day Doctors Without Borders will relay questions about tough cases from its physicians in Niger, South Sudan and elsewhere to its network.

Likewise, shifts of doctors and nurses work around the clock in Mercy Health’s new Virtual Care Center, a “hospital without beds” that provides remote support for intensive-care units, emergency rooms and other programs in 38 smaller hospitals across the Southeastern US. Many of the included healthcare centers don’t have a physicians on-site 24/7.

In the TeleICU section of Mercy, critical-care doctors sit at oversized video monitors that continually collect data on every far-flung ICU patient and can spot signs of imminent trouble. If a patient needs attention, Mercy physicians can zoom in via two-way camera—close enough to read the tiny print on an IV bag.

“It’s almost like being at the bedside…I can’t shock a patient, but I can give an order to the nurses there,” says Vinaya Sermadevi, a critical-care specialist.

In the past year, ICUs monitored by Mercy specialists have seen a 35% decrease in patients’ average length of stay and 30% fewer deaths than anticipated. “That translates to 1,000 people who were expected to die who got to go home instead,” says Randy Moore, president of Mercy Virtual.

So is the Virtual Doctor is on the Rise?

In the last year, the number of virtual doctors visits has grown 12-fold, from 1 million to 12 million. Additionally, the number of employers offering telemedicine benefits has grown from 48% to over 75% since last year.

So what does this rise prove? Well for starters, 72% of hospitals and 52% of physician groups offer telemedicine programs. It’s these kinds of positive statistics that show us telemedicine is on the rise and here to stay.

As a measure of how rapidly telemedicine is spreading, consider this: In 2015, over 15 million Americans received some kind of remote medical care; and that number is expected to grow by roughly 30% just this year.

However, none of this is to say that telemedicine has found its way into all corners of medicine. A recent survey of 500 tech-savvy consumers by HealthMine found that 39% hadn’t heard of telemedicine, and of those who haven’t used it, 42% said they preferred in-person doctor visits. In a poll of 1,500 family physicians, only 15% had used it in their practices—but 90% said they would it if were appropriately reimbursed.

What’s more, for all the rapid growth, significant questions and challenges remain. Rules defining and regulating telemedicine differ widely from state to state and are constantly evolving. Physicians groups are issuing different guidelines about what care they consider appropriate to deliver in what forum.

Some critics also question whether the quality of care is keeping up with the rapid expansion of telemedicine. And there’s the question of what services physicians should be paid for: Insurance coverage varies from health plan to health plan, and a big federal plans covers only a narrow range of services.

Telemedicine’s future will depend on how—and whether—regulators, providers, payers and patients can address these challenges.