I have a tough time understanding why anyone would worry about the shortage of doctors, or for that matter, the cost of health care. I’ve met countless people who enjoy nothing more than giving medical advice. Unlike folks with M.D. after their names, they’re willing to work nights, weekends and holidays, for absolutely no cost.

Just last week, I was chatting with a woman at the Y when I mentioned that I run. I thought most medical practitioners considered running a healthy habit. No way, I learned. She informed me that running was compressing the discs in my spine. I’ve never noticed my spine doing anything beyond holding me up. Apparently, neither did my other doctor, the one with a license to practice medicine. I admitted that I probably should run on dirt trails. But, I said, I run at 5 a.m. to avoid the Florida sun and feel safer in well-lit neighborhoods than dark woods.

I thought she’d praise me for protecting myself from skin cancer. Instead, she gave me a concerned look.

“So you run on the roads?” she asked.

I was starting to realize that admission had been a mistake.

She informed me that I would get cancer and die. All the proof I needed was right there at the Y. In recent years, three female employees had gotten cancer. Obviously, she pointed out, it was from sucking exhaust fumes while running in the road. The next morning, I huffed carcinogens with friends as willing as I am to flout medical wisdom.

Another prime site for free medical advice is any store that sells products to treat medical conditions. I made that discovery a couple years ago shopping in a cosmetics store for something to camouflage a rash on my face. The clerk not only found the perfect product; she also gave me a free medical diagnosis. When I heard the word rosacea, I was crushed. Rosacea has no cure. I imagined going through life with Bill Clinton’s nose until a couple days later, when the rash disappeared.

Oddly, about the only people who refuse to give free medical advice are those trained to give medical advice. Take my buddy Joe. People who’ve known him 10 years have no idea he’s a retired orthopedic surgeon. He knows I know. But when he recently saw me with my wrist in a splint, do you think he asked about it? Not a word. I guess he knew I’d have plenty of unlicensed docs for that.

One of them was a teacher’s aide who honed her medical skills handing out Band-Aids and escorting students to the school clinic. She told me that because I had a splint and not a cast, I was bound to break my wrist again.

Then there are the champions of alternative medicine. Most of these folks were born in the Jurassic Era, if not earlier. I remember my grandfather walking around with a potato in his pocket to cure arthritis. My father treated his arthritis with gin-soaked raisins. They didn’t work well. Maybe he would have had better luck if he’d put them in his pocket.

Another senior family member recently advised me to load up on water just before going to bed. When I said that would make me wake up once or twice a night to relieve myself, she said that’s the idea. We humans may have evolved to walk upright, but our kidneys apparently haven’t caught up. She said they work best when we’re lying down. Ceiling painters and prostitutes must have the healthiest kidneys on Earth.

Of all the people advising me on my health, the few I actually listen to are runners, especially if they’re faster than me. So when two suggested I treat my aches with DMSO, I did. For a couple years, I rubbed the gel on my left heel before every race. The pain went away. I ran some of my fastest times, which is a shame, because I felt so guilty using it that I quit. The problem is that the Food and Drug Administration never approved DMSO for humans; it’s for horses.

The way I ignore people’s medical advice, I’ll undoubtedly end up with cancer, a compressed spine and God knows how many more broken left wrists. Even worse, I’ll never run like Seabiscuit again.