Q. What is a pulse oximeter, and do I need one?
A. A pulse oximeter is a small device that measures the saturation level of oxygen in your blood and your pulse rate, typically by clipping onto your forefinger. Normal oxygen levels typically range between 95 and 100 percent at sea level (lower at higher altitudes); anything below could indicate a problem with the lungs or the heart, such as chronic obstructive pulmonary disease or pneumonia.
With Covid-19 affecting communities nationwide and globally, some experts consider an investment in a battery-operated fingertip pulse oximeter worthwhile. Because the disease typically attacks the lungs, a pulse oximeter can provide a quick, inexpensive way to monitor respiration at home and get ahead of a potentially worsening situation. If oxygen saturation levels drop, a user can share that information with a doctor so a decision can be made about whether further medical care is needed.
Some health care practitioners have described the pneumonia that occurs with Covid-19 as silent, in that patients may not realize they’re being deprived of oxygen until their saturation levels are dangerously low. In these cases, they say, people who suspect they’re ill but aren’t experiencing shortness of breath can use pulse oximeters to get a better picture of the state of their lungs.
If their levels are low, they can seek medical care before the situation becomes truly dire—which, according to doctors, can happen quickly with Covid-19. And, while a home model may not be 100 percent accurate, it can be useful in monitoring your oxygen level and whether it’s trending downward from what’s normal for you. It’s best to use a pulse oximeter as a monitoring tool when you’re ill, not as a measure that things are right or wrong with your health.
If you’re in the market for a pulse oximeter, try to find one that’s FDA cleared or approved. A 2016 study of six pulse oximeters that weren’t FDA cleared found a wide variety in accuracy among the models, with most having highly inaccurate readings.
Prices vary, typically from $25 to $100, but a basic model that measures pulse and oxygen levels works just as well as a high-end model. Your choices may be limited, however, since demand has recently risen. Oximeters are typically sold by health-supply stores, drugstores like Walgreens and CVS, big-box stores like Target and Walmart, and Amazon.com. Some manufacturers, like AccuMed, sell them directly to consumers on their websites.
This article first appeared in the July 2020 issue of UC Berkeley Health After 50.
Also see How to Buy a Home Blood Pressure Monitor.