Urgent care centers or “walk-in clinics” are popping up all over the place. Some people refer to them as a “doc in the box.” They offer convenience and same-day service without an appointment. So, when should you use them instead of your doctor?

The name should give you a hint – “urgent care.” They’re good for urgent problems that don’t quite fit into the “emergency” category. They became a popular place to be seen when the Covid pandemic hit and people needed to find out if they were Covid positive. Going to an emergency room didn’t seem right and they’re usually associated with long wait times. Going to an urgent care center got you a quick answer to the question of whether or not you had Covid. Primary care physicians generally discouraged Covid visits anyway.

But what about when your blood pressure is high? The urgent care center will probably give you a temporary fix for that problem, but won’t do the necessary testing and follow-up that is really needed. They also won’t keep up with your vaccinations and do needed health screening exams.

Sumathi Reddy, writing in The Wall Street Journal, says the ubiquity of walk-in and urgent-care clinics has changed the way many of us seek treatment for what we think are minor ailments such as the flu, pinkeye or a pulled muscle. Instead of trying to make an appointment with our primary care doctor, who might not be able to see you the same day, we often just go to the walk-in clinic.

“The urgent care center is going to focus on the problem at hand and move on, but their primary care is going to try to think more comprehensively,” says Dr. Ateev Mehrotra, a professor of healthcare policy at Harvard Medical School who has researched urgent care clinics.

The number of urgent care centers has grown by about 14% every year since 2016, says Lou Ellen Horwitz, CEO of the Urgent Care Association, a trade group. Mehrotra’s research found that the number of urgent care center visits per person more than doubled between 2008 and 2015.

When to see urgent care

Urgent care is a great place to go to address immediate medical concerns when you can’t get an appointment with your doctor or it’s a weekend or evening and the office is closed. (If it’s potentially life-threatening, though, you should go to the ER.) Urgent care centers can be better suited to treat certain injuries than your doctor’s office. Sprains, strains, cuts and burns are all things that urgent care centers are good at treating, says Dr. Rupal Bhingradia, a family physician who works at an urgent care clinic in New York.

Many urgent care centers have equipment that allows them to do more than your average primary care practice. “They’ll often have X-ray equipment, CT scans, ability to do sutures, IV and so forth,” says Mehrotra. “In general most primary care practices cannot provide those kinds of services.”

There are certain times where you should skip urgent care and head straight to the emergency department, says Friedman. This includes if you have any symptoms that might be a heart attack or stroke, such as chest pain or face numbness. If you’re struggling to breathe or have severe abdominal pain, it makes more sense to head to the ER rather than wasting time at an urgent care clinic that may end up sending you there, he says.

When to see your primary care doctor

The number one challenge with urgent care centers is that they generally don’t have access to your electronic health record, which details your medical history and other important medical information, says Mehrotra. An urgent care doctor isn’t tracking your health over the long term or looking for patterns that may require new treatments. So especially if you have a complicated health history or chronic illnesses, relying too much on urgent care for treatment may mean you miss bigger problems.

Cost can also be a factor when deciding whether to go to your doctor’s office or urgent center, says Mehrotra. It typically will cost more to go to an urgent care clinic than your primary care doctor’s office because they typically have more overhead expenses with longer hours and extra equipment. But it will be less than going to the emergency room.

You shouldn’t use an urgent care clinic as a replacement for a family physician or primary care doctor, says Bhingradia. Primary care doctors will manage your overall care rather than simply treating a one-off complaint, and should be your first point of contact for routine healthcare needs such as vaccinations, screenings and treatment of chronic conditions, she says.

In general, if the problem can’t wait for your doctor’s availability, but isn’t a true emergency, go to the urgent care center. If it can wait, see your primary care doctor.