Skip to main content

You probably shouldn't use your phone to check your blood oxygen saturation level (SpO2)

Samsung Galaxy S5
Samsung Galaxy S5 (Image credit: Android Central)

We've all witnessed the run on commodities like toilet paper, beans, and even rice that has taken place over the last few weeks. Still, one type of item that is becoming increasingly difficult to find has kind of surprised me. Which item is that you ask? Pulse oximeters. These are medical devices that can measure the oxygen levels in your blood, or your SpO2, as it is more commonly known.

If you're wondering why this is important, you're either blissfully unaware, or you've been really good at socially distancing from the news. You see, the ongoing virus that caused this global pandemic is particularly aggressive towards those with weakened immune systems and compromised breathing abilities, and it is these folks who may have lower concentrations of blood oxygen. So it is understandable that more people are trying to equip themselves to better track and monitor their health during this scary time.

Since pulse oximeters are in shorter supply and are an additional expense if you don't already have one, it stands to reason that people are looking for alternative means of measuring their SpO2. They are doing a lot of searching on the internet for ideas, but the solutions they're finding are not always the most helpful.

Phones and apps

Samsung Galaxy S7 Active

Source: Android Central (Image credit: Source: Android Central)

One older "solution" that keeps popping up is the concept of using the camera or sensors on your smartphone to measure your SpO2.

For years, phone manufacturers like Samsung and numerous app developers have pitched the idea that you could use your phone to measure heart rate and even blood oxygen data, but as the evidence came in that this was not the most effective solution, and more and more wearables like smartwatches started coming on the market, those phone-based solutions began to fade. However, they didn't disappear entirely.

You see, while Samsung removed dedicated health sensors from their phones a couple of generations ago, it is still possible to get a SpO2 reading through the Samsung Health app and the camera on more recent devices. There are even apps on the Google Play Store and Apple App Store that still say they can measure SpO2 through the camera sensor.

Even here on Android Central, we recently had a six-year-old post covering Samsung's addition of SpO2 monitoring to their phones and the Samsung Health app that spiked in popularity and search traffic over recent weeks. Now, of course, we have since updated the piece to be as accurate and current as possible, but it doesn't address or answer the question of whether or not you should use a device like a smartphone to measure your SpO2.

In fact, the consensus among the medical community seems to be that using your phone's camera, sensors, and/or apps is probably not the best or most accurate way to measure SpO2. So what should you do?

via GIPHY

Listen to your doctor

Fitbit Versa 2

Source: Android Central (Image credit: Source: Android Central)

The medical community has been sour on the efficacy of measuring SpO2 with phones for some time, and even newer research affirms this position, likely prompted by a recent spike in worldwide interest in this topic.

According to the Center for Evidence-Based Medicine at Oxford University:

There is no evidence that any smartphone technology is accurate for the measurement of blood oxygen saturation. Furthermore, the scientific basis of such technologies is questionable. Oxygen saturation levels obtained from such technologies should not be trusted.

Now, despite the skepticism of SpO2 tracking with smartphones themselves, many consumer-grade options are considered more reliable for health tracking, such as certain smartwatches and dedicated pulse oximeters.

Smartwatch manufacturers such as Fitbit and Garmin offer devices that have SpO2 sensors, which they say can detect variations in your blood oxygen levels. Other notable health wearables from Withings and Apple claim to offer this functionality as well. However, the Withings and Apple offerings are awaiting regulatory approval to activate the sensors into some of their most recent devices. Even the smartwatches that can monitor SpO2 should not be used exclusively as diagnostic devices, and you should consult with a medical professional if you are concerned by any of the readings you get from your wearable.

Don't just rely on your devices. Consult with a medical professional if you are concerned about your SpO2 readings.

If you can find a recommended and reliable dedicated pulse oximeter, that is probably the best home-based solution for monitoring your SpO2. Some of these devices are "smart" in the sense that they can pair with an app on your smartphone to relay data via Bluetooth, but many don't have this functionality. We recommend that you consult your doctor or a trusted health professional for recommendations when it comes to purchasing dedicated health technology like this.

Jeramy is proud to help *Keep Austin Weird* and loves hiking in the hill country of central Texas with a breakfast taco in each hand. When he's not writing about smart home gadgets and wearables, he's defending his relationship with his smart voice assistants to his family. You can follow him on Twitter at @jeramyutgw.

4 Comments
  • Samsung Health was always spot-on compared to dedicated oximeters back in the day, so I would still trust it to detect a 20%+ change. At least enough to set off alarm bells.
  • When I was a medical assistant and had the S6 I would compare it to our instruments and I was surprised to how effective and accurate it was. Makes sense that they removed them from your devices so you can get a Galaxy Watch, but I still trust it and use it daily.
  • My wife spent about an hour last night testing this with her s10+ on her and me and found wildly varying inconsistent results. She said it seemed the results were slightly more consistent and probably more accurate when she took off her case but she knows our normal o2 stats and they still weren't near those marks. She wasn't even impressed when checking our bpms since she can check those without a separate machine.
  • The $35 Huawei Honor 5 band has a pulse oximeter. They're readily available on eBay.