Virtual doctor visits are growing in number and popularity as clinic systems learn what types of conditions they can treat online.

Winona Health is the latest Minnesota clinic system to add the approach, reaching an agreement to offer SmartExam virtual visits that can assess patients in minutes for any of 430 medical conditions.

“People will be able to access care from anywhere — whether they are at their desk, on vacation or at home under a blanket on their couch,” Rachelle Schulz, Winona Health’s president and chief executive, said in a news release.

Winona Health is the first system in Minnesota to add SmartExam, which was created by of Portland, Ore. But other virtual clinic platforms have emerged.

Bloomington-based HealthPartners created virtuwell in 2010, and has since provided a half million consultations to patients in 13 states. Online visits have increased as much as 30 percent per year, said Anne Sandell, HealthPartners spokeswoman.

Virtuwell has expanded to cover more conditions and to allow patients to upload photos of rashes or pinkeye or other problems for practitioners to evaluate, she added. “Cameras on phones have improved year over year, and the resolution is powerful.”

No visits are exclusively virtual, or result in computer-generated diagnoses. Patients enter symptoms and answer questions, and the resulting information is then forwarded to practitioners who issue prescriptions or medical orders.

Virtuwell is staffed by nurse practitioners.

SmartExam is used nationwide, but local patients receive advice from local practitioners, said Ray Costantini, chief executive of Winona Health will use its own practitioners, for example, when it starts seeing patients via SmartExam early next year.

Virtual visits lack face-to-face benefits, but have other advantages compared to the use of videoconferencing, or telemedicine, in clinical care, Constantini said. Video equipment can be cumbersome and slow some doctors down.

Costantini said a majority of doctors and patients interact on SmartExam via mobile phones. Machine learning has taught the system to handle more conditions and to quickly identify patients who need face-to-face care in clinics or hospitals, he added.

Lost in online visits are the “doorknob” moments when hesitant patients wait until exams are over to tell doctors about underlying or embarrassing medical concerns.

But confidential online visits can make patients more comfortable raising embarrassing concerns in the first place, Constantini said. “Patients are actually more comfortable reaching out.”