A few nights a week after work I have to stop by the store for this or that.

In the last 1-2 months there’s always been a couple at the parking lot exit, both in wheelchairs, with a big sign asking for money to help one of them beat cancer. They even have the amount listed.

I’ve never given them anything. I generally don’t do that with panhandlers, mainly because I have no way of knowing if the whole thing is real or a show. Sadly, it wouldn’t be surprising to find out neither of them had cancer, and they were spending the money on cigarettes and the local casino.

But, by the same token, they could be quite legitimate. The American health care system is full of cracks that seriously ill people can slip through. One recent survey found that about 30% of Americans had trouble paying their medical bills.

It’s easy to look at people like this and think, “I’ll never let that happen to me.” We assume they must be smokers, or irresponsible spenders, or some other reason that makes us feel we won’t stumble into the same pitfalls. That’s reassuring, and sometimes true, but not always. And probably more often than we want to realize.

The world is full of people and families devastated by bad luck. Through no fault of their own, they develop a terrible medical condition or suffer grievous injuries, and suddenly, decent, hard-working, previously healthy people are facing foreclosure and financial ruin. It could, quite literally, be any of us.

Case in point: My family has good insurance and has averaged $10,000 in out-of-pocket medical expenses per year for the last several years. That’s for routine stuff: meeting deductibles, copays on medications, tests, and doctor visits, a few ER trips, etc. The only real “surprise” in there was when my wife broke her leg and needed surgery.

Fortunately, we’re able to afford that, and I’m not complaining. A broken leg is at least (hopefully) a one-time event. But what about an average, working, middle-class family with the same insurance who had a much more serious, chronic diagnosis? It isn’t hard to see how easy it is to go from a comfortable financial position to taking second jobs and thinking twice about which groceries to buy. Some will make it, and others may end up asking for money on street corners.

If the panhandlers really did have legitimate medical issues, I might be willing to help out. I give to charity. My grandmother and parents stressed that value to me, and I try to teach it to my kids. But, sadly, we live in a world full of con artists who try to make money by taking advantage of caring peoples’ feelings. Look at all the scams that immediately cropped up following the recent hurricane and wildfire disasters. Without knowing the truth, I’d rather give to an organization like the Salvation Army or Red Cross, hoping they have more experience than I do in sorting out who’s really in need.

As a doctor, I also try to justify it by thinking about how much care I do for “free.” This includes uninsured hospital patients we all see on call, knowing we’ll end up writing their bill off as a loss, and bounced checks for copays and deductible portions that we know we’ll never see.

But, no matter how I try to rationalize it, it still bothers me when I see them sitting there as I leave the store. I don’t know if they’re legitimate. But if they are, they aren’t alone, and there’s something seriously wrong with our health care system.

Dr. Block has a solo neurology practice in Scottsdale, Ariz.