One recent afternoon, Christine Ryan didn’t head to the doctor’s office or emergency room when her ear was aching; she went to her local CVS store in Cambridge.

Within 20 minutes, Ryan had been diagnosed with an ear infection and was picking up medicine and heading back to work. “This was the quickest visit I’ve ever had in my life,” the 24-year-old human resources professional said.

Consumers like Ryan increasingly are looking for faster and more convenient options to get basic medical care, and retailers like CVS are filling the gap with walk-in clinics and other services. That’s forcing traditional health care providers, from small doctors offices to big hospitals, to react.

At Atrius Health, a large medical group, more doctors are leaving their doors open until 8 p.m. Tufts Medical Center is taking online appointments for its emergency room. Several hospital networks are building walk-in clinics for urgent care. Doctors have started seeing patients through video chats. And apps are being built that will let consumers make appointments and view medical information from their phones, the way consumers already access so many other services.

“This represents a huge paradigm shift in health care,” said Normand E. Deschene, chief executive of Wellforce, the parent company of Tufts Medical Center and Lowell General Hospital. “The systems that are going to succeed are those that are going to embrace it because this is what the consumers want. Most industries follow what their consumers want. Health care should be no different.”

More options are generally good for health care consumers. But some experts are concerned that care will become more fractured and less coordinated if patients seek services at many different places. And it’s unclear whether this shift will lead to lower costs.

In Massachusetts, CVS leads the pack of retailers moving into health care. The Woonsocket, R.I., company operates 1,000 MinuteClinics in 31 states, and expects to add 500 more by the end of 2017. It dominates the retail clinic market in Massachusetts, with 58 clinics here. MinuteClinic revenue increased 21 percent in the quarter ended June 30, compared with the same period last year.

MinuteClinic’s president, Dr. Andrew J. Sussman, said CVS expects the business to continue to grow because of the aging US population, the nationwide shortage of primary care physicians, and a rise in chronic diseases.

Health care is a huge and growing part of the economy, with spending forecast to reach $5.4 trillion by 2024 — nearly 20 percent of gross domestic product, according to federal government estimates.

“What’s attracting retailers and other companies from the outside is the financial opportunity,” said Mark Grube, managing director of Kaufman Hall, an Illinois consulting firm. “Retailers have left it alone for decades, but now they see opportunity because traditional providers have not always been responsive to the changing needs of consumers, which creates opportunities for others to step in.”

As retailers expand their health care offerings, so too are traditional health care providers. Partners HealthCare, Lahey Health, Steward Health Care System, Beth Israel Deaconess Medical Center, UMass Memorial Health Care and others all are building urgent care sites, or partnering with companies that run urgent care clinics. The clinics are staffed by physicians and other health care workers.

The goal is to offer patients with urgent medical issues — not emergencies — an alternative to emergency rooms and doctors’ offices where the waits can drag on for hours. They cater to people with problems like sore throats, sprains, cuts, and rashes.

Like retail clinics, urgent care centers tend to be located along busy streets and shopping areas.

“We are located in true retail settings,” said Dave Adams, president of the AFC Doctors Express clinic across from the Burlington Mall, which is affiliated with Steward Health Care. “[Our clinics] are next to Chipotle and Five Guys. It’s a real estate play as much it’s a health care one.”

Thomas Lourdeau of Arlington wandered into the clinic on a recent morning, when his regular doctor’s office couldn’t fit him in. Lourdeau, 28, left half an hour later with a prescription in hand for his sore throat.

“It’s my first time here,” he said, “and I’ll be back.”

Atrius Health, the Newton-based doctors group, opted not to build urgent care clinics, but instead is expanding night and weekend hours at some existing medical offices. Atrius also is rolling out software to allow patients to book appointments online.

“Our response is to extend hours and make walk-ins and online booking easier and more available for patients,” said Dr. Richard Lopez, chief medical officer.

Lowell General Hospital has moved some specialists from its city campus to suburban clinics that patients find more convenient to access. It is also testing a telehealth program to allow doctors and patients to talk remotely.

Partners is among the health systems working on an app so patients can keep up with their health care on their smartphones, the same way they monitor their bank accounts and travel plans.

CVS and other retailers say they’re trying to give consumers more options, not replace traditional health care companies. Sussman said CVS’s experience as a retailer has informed its approach to health care. Half of patients at CVS MinuteClinics are seen on weekends or evening, periods when stores remain open and traditional doctors’ offices close. Sussman said the company is transparent about prices and posts costs for services, which is important to patients with high deductible health plans or no health insurance.

The clinics, staffed by nurse practitioners, use a kiosk check-in system and send waiting patients a text when it’s time for their appointment. “Patients are looking for easy access to care, good quality and low cost,” Sussman said. “That’s part of what’s making us so successful.”

In other parts of the country, retailers like Walgreens, Rite Aid, and, Walmart also are building clinics or hiring health care providers to provide basic medical services for people who lead mostly healthy lives, as well as those with chronic diseases.

Even supermarkets are joining the mix. The parent company of Stop & Shop has deployed nutritionists to many stores, including the one in Chelmsford. It has trained hundreds of pharmacists to help people with diabetes take their medications correctly and eat healthier diets, and is even running some classes to counsel diabetics on managing their disease.

If Stop & Shop’s pharmacy customers keep their chronic diseases under control, the company gets higher payments from insurers, said Brad Dayton, vice president of pharmacy for Ahold USA, the parent of Stop & Shop.

“We’re in a unique position,” Dayton said. “Our stores are food stores, plus we have the health and wellness capability. We’re able to combine that.”

Image credit:  Ilmicrofono Oggiono | Flickr
Via The Boston Globe