If you have sleep apnea and your doctor has recommended a continuous positive airway pressure (CPAP) machine, the price alone might take away your breath.

A new one ranges from $600 to $2,000. Insurance often covers it, but if you don’t have insurance—or you have a minimal policy—you might be tempted to head to Craigslist or some other used-goods site to get a cheaper used one.

Resist the temptation. It could be dangerous. There’s a better way.

A USED CPAP: RISKY BUSINESS

The US Food and Drug Administration doesn’t authorize buying or selling a secondhand CPAP machine, a prescription-only treatment device that uses mild air pressure to keep the airways open in your nose and throat while you sleep—but it’s common. In a new study, researchers checked Craigslist for one month in 18 US cities and found 270 advertisements for secondhand CPAP machines.

What’s wrong with buying a used machine? Hygiene, for one. It’s common for a machine to harbor pathogenic germs from the previous patient—which then get pushed into your lungs. That’s especially true if you buy a machine with a used mask, used filter and used tubing.

While you can buy new replacements for the used mask, filter and tubing, and then clean the machine carefully yourself, you are unlikely to be able to calibrate it correctly yourself. If you buy a used CPAP machine, the pressure might be too low, in which case the machine won’t be effective. Or it could be too high, which could be uncomfortable and could even lead to other medical problems, such as a related problem called central sleep apnea.

The chances are also good that you’ll be buying an outdated device. These days, there’s a strong trend toward new “smart” PAP machines—called APAP, for “automatic positive airway pressure”—which are auto-titrating, which means that they automatically adjust airflow to your breathing rate. Yet only 10% of the used-CPAP machine ads found by researchers mentioned an auto-titrating feature.

Finally, if a mask is too small or too large for you, chances are you won’t wind up using the machine at all.

A SAFER, INEXPENSIVE ALTERNATIVE

Instead of taking your chances on a used CPAP machine bought from who-knows-who, if you are having trouble affording this lifesaving piece of equipment, you can buy a used one from the American Sleep Apnea Association’s CPAP Assistance Program.

ASAA takes donations of CPAP devices in good condition, cleans them professionally—and then, if necessary, reprograms them for a buyer based on the buyer’s prescription. They also offer many thousands of APAP machines with auto-titration features (which don’t need to be reprogrammed). Check with your doctor to find out which kind of machine is best for you.

Not only will the machine be customized for your needs, you’ll be sure to get all the parts and accessories you need, including the owner’s manual. You’ll get new tubing, a new filter, a new mask, a carrying case and a patient manual.

The charge for the machine and the programming is only $100. If all you need is a brand-new mask, which typically costs $185, you can get that for $25. To date, the association has distributed more than 5,000 CPAP machines.

You’ll not only save money but will breathe easier knowing that you have a safe device. To learn more ways to make CPAP work for you, and for tips on non-CPAP alternatives to treating sleep apnea, see Bottom Line’s article “How To Finally Fix Your Sleep Apnea.”