COVID-19 is a respiratory illness that can cause lung complications including pneumonia and acute respiratory distress, both of which deplete oxygen levels in the body, according to Johns Hopkins Medicine. Some COVID patients either do not notice or do not have other illness symptoms as their oxygen levels drop, according to Dr. Richard Levitan, who wrote in an op-ed in the New York Times that using pulse oximeters and monitoring blood oxygen saturation can help individuals recognize signs of COVID-19 before they notice any other symptoms. Most at-home pulse oximeters range in price between $25 and $200, and can be bought with pre-tax money from your FSA or HSA account. Increased demand for pulse oximeters was likely driven by people who wanted a relatively inexpensive device that gives out a number for assessing their health, rather than trying to gauge symptoms based on how they feel.
One thing Rizzo says to avoid (unless your doctor tells you otherwise) are phone apps that claim to work as pulse oximeters. “The traditional pulse ox works by shooting two wavelengths of light into the tissue. It’s not just white light, which is what most of the phone apps would use,” he says. This means the technology of a phone oximeter app is fundamentally different than an actual device, so if you’re relying on an oximeter for clear, consistent data, it’s best to stay old-school until more testing is done on phone oximeter apps. (Physical pulse oximeters that link to a phone app to track readings are medically fine, though may cost you more for that feature.)
If you do get an oximeter, Rizzo recommends speaking with your physician about it so you have context for what the numbers it displays mean for you. “The more information you have about what to do about the number on the pulse oximeter, the better you’ll be able to handle it,” he says. “It’s one number to be used along with everything else when you either call or do a televisit with your healthcare provider and say, ‘This is how I’m feeling,’ [and also mention the number on your pulse oximeter],’” he says. “It’s just additional information. It’s a matter of access and affordability.”