Do you know the emergency room phone number offhand? Of course you do — it’s 911. Chances are your phone even has it on speed dial. But can you name the number for your local urgent care clinic? Of course not. If you’re like the vast majority of Americans, you’d have to go look it up.

That’s because an estimated 55% of urgent care facilities in the U.S. have only been open for around five years or slightly longer, according to a recent poll from the Urgent Care Association of America. But the urgent care movement has its roots in the 1970s and has only been gaining ground in the wake of President Obama’s passage of the Affordable Care Act. American cities need more primary care physicians, and while patients wait for them to graduate from med school, they’re frequenting urgent care to fulfill their non-life-threatening needs.

In fact, an estimated 27% of all ER visits could actually be treated at a 24 hour urgent care facility. That’s because urgent care specializes in treating respiratory problems, sprains and bone breaks, minor skin problems, coughs, flu symptoms and other minor ailments and injuries. Urgent care clinics are now even offering x-rays and prescription pick-ups right in the very same offices where the doctors see patients.

Of course, there’s the “so what?” factor that always gets brought up when it comes to urgent care. Why can’t a patient merely make an appointment with his or her physician instead? Why wouldn’t you go to the ER if you thought you had something that necessitated emergency care? The answers, respectively, are that you can and you would. But the issue of modern medicine is a bit more complex than that.

Physicians Are Filling Up Their Appointment Slots Quickly

As a direct result of the ACA, more primary care physicians are booking up. More patients are now insured, which means more spots in the scheduling, which means less actual time for doctors to spend with their patients. As a direct result of this, plenty of urgent care centers have taken to offering routine physicals in addition to their continuing treatment of minor injuries and illnesses.

Emergency Rooms Are Overcrowded, So Say the Latest Numbers

Make no mistake: if it’s a true emergency, you need to go to the hospital. There’s really no way around it. But if you’re unsure of the situation and can’t get an appointment with your regular physician, that’s when 24 hour urgent care is a good backup plan. That’s part of the reason, too, why so many of these clinics are indeed open all night — you never know when a medical issue is going to take hold.

With all this in mind, you should have a better understanding of when the right times are to venture to a clinic — whether or not it’s a 24 hour urgent care facility or not. For more information, always consult a doctor. More like this blog.