Blood Oxygen Monitor


Estimated oxygen variation (EOV) is an estimate of the changes in your blood oxygen saturation levels. For instructions, see How do I track my estimated oxygen variation in the Fitbit app? The EOV feature is designed to see specific events overnight when your blood oxygen saturation levels varied, which could indicate breathing disturbances. Zacurate Premium 500E Sporting/Aviation Fingertip Pulse Oximeter Blood Oxygen Saturation. Buy Oximeters online and view local Walgreens inventory. Free shipping at $35. Find Oximeters coupons, promotions and product reviews on On the other end, if you're a sports enthusiast involved in many high-altitude activities or a pilot, a blood oxygen saturation level monitor can be a handy tool to help you perform at your best. Whichever end of the spectrum you belong on, make sure you're equipped with the.

It could help if you have COVID-19, but whether everyone needs one is still unclear.

It’s fair to say that the novel coronavirus pandemic has changed the way people shop—and also the items they shop for. There has been a shortage of things one might expect: toilet paper, disinfectant wipes, and thermometers. But, there are other—more surprising—items like yoga mats, yeast, and, more recently, pulse oximeters.

So, what, exactly, is a pulse oximeter?

It’s an electronic device that clips onto a patient’s finger to measure heart rate and oxygen saturation in his or her red blood cells—the device is useful in assessing patients with lung disease. Pulse oximeters started to fly off store (and online) shelves when people learned that low oxygen saturation levels can be a sign of COVID-19.


The logic is that shortness of breath, a symptom of the disease, may not be easy—or even possible—for a person to reasonably self-assess. What’s more, doctors report that some COVID-19 patients suddenly develop a condition called “silent hypoxia,” where people look and feel comfortable—and don’t notice any shortness of breath—but their oxygen levels are dangerously low. It happens to patients both in the hospital and at home, but it is a particular problem in the latter case because the symptom may indicate severe COVID-19-related pneumonia, requiring a ventilator. That’s why some people may want or need to monitor their oxygen saturation levels at home.

Should you buy a pulse oximeter?

There is debate among doctors about whether or not people need a pulse oximeter in their medical supply kits at home. “In normal times, unless a patient has true lung disease, there is no need for them to use pulse oximetry monitoring,” says Denyse Lutchmansingh, MD, a Yale Medicine pulmonologist. But these aren’t normal times. The American Lung Association advises against buying pulse oximeters unnecessarily and recommends people focus their awareness on other COVID-19 symptoms. However, in a recent New York Times opinion piece, an emergency physician from New Hampshire said if resources were directed toward earlier detection of silent hypoxia, doctors could do more to keep those patients off ventilators.

There are additional factors to consider, says Dr. Lutchmansingh. One is that knowledge of the virus is rapidly changing, which means advice can shift, as it did when the Centers for Disease Control and Prevention (CDC) changed its face mask recommendation in April to one that urges people to start wearing cloth masks in public. “We’re working very fast with limited pre-existing data. We are extrapolating a lot based on prior coronavirus infections, like severe acute respiratory syndrome [SARS] and Middle East respiratory syndrome [MERS],” she says.

At this point, Dr. Lutchmansingh says the benefits of pulse oximetry monitoring are most clear among patients who have COVID-19 symptoms such as cough, fever, and shortness of breath. “If you are symptomatic that is a reasonable time to check your oxygen. That is something we’ve been trying to do from an outpatient standpoint,” she says. “We have COVID-19 patients who we are monitoring at home and one of the deciding factors for bringing them into the hospital is their oxygen level.”

But for people who are young and healthy—and have no COVID-19 symptoms—she questioned the need to buy a pulse oximeter.

How to buy it, what to do with it

If you do have a pulse oximeter and are checking your oxygen levels, it’s important to know that a level between 95 and 97% is considered normal by the American Lung Association; anything below that would be a reason to call a doctor, and anything under 90% would be a reason to go to the emergency room.

Dr. Lutchmansingh also advises people who plan to use a pulse oximeter to ask a medical professional to guide them. “It’s helpful to know your baseline level,” she says. “If there are changes, a medical professional can talk about what’s causing those changes and take any additional measures to investigate it.” Changes might be related to a non-COVID pulmonary problem that may be undiagnosed, such as asthma or unrelated pneumonia, she says. In addition, your reading may be inaccurate if your fingernails are dirty or you have artificial nails or are wearing nail polish.

Best Finger Oxygen Monitor

As far as which pulse oximeter to buy, “There is no standardization,” she says. “You are buying in good faith.” According to Consumer Reports, prices for pulse oximeters range from $25 to $100, if you can find one, as shortages have been reported. Phone apps and exercise trackers like Fitbits are not the best tools for checking oxygen levels, Dr. Lutchmansingh says. “One can always go the route of ‘something is better than nothing,’ but we don’t know how accurate they are,” she says. “But if you have one of those things [apps or trackers] and the numbers are low, I would still advise that you talk to your doctor.”

Buying a pulse oximeter to ease the anxiety

There is another consideration—some people stock up on anything that eases their fear and anxiety, says Dr. Lutchmansingh. “There is such wide variance to this disease,” she says, explaining that it’s still difficult to predict who will become severely ill, and it’s understandable that people would want to be prepared for any eventuality. “There is the medical component to this, and then there is the anxiety component. People are scared. If they feel there is some action they can take, some sort of monitoring they can use, it’s hard not to take advantage of it,” she says.

“However, it’s not necessarily helpful for people to buy things just to have them, because there is a difference between gathering data and using data,” she says. “It’s not just information in a bubble. You can get all your numbers, but if you don’t know how to interpret them, all you have are numbers.”

Meanwhile, shortness of breath and low oxygen levels are just two possible symptoms of COVID-19, and it’s important to know all of the symptoms, Dr. Lutchmansingh says. The CDC provides a list of symptoms that could appear anywhere between 2 to 14 days after exposure to the virus that causes COVID-19. That list includes cough, fever, shortness of breath, difficulty breathing, chills, repeated shaking with chills, muscle pain, headache, sore throat, and loss of taste or smell.

Patients and members of the community who have questions can call the Yale Medicine/Yale New Haven Health Call Center COVID-19 hotline at 203-688-1700 (toll-free, 833-484-1200).

Click here to read about a philanthropic gift of 100 wearable pulse oximeters to the Yale Medicine Department of Internal Medicine.

5 Things Everyone Should Know About the Coronavirus Outbreak

Measurements taken with the Blood Oxygen app are not intended for medical use and are only designed for general fitness and wellness purposes.

The Blood Oxygen app is only available in certain countries and regions. Learn where the Blood Oxygen app is available.

What is blood oxygen

Your blood oxygen level represents the percentage of oxygen your red blood cells carry from your lungs to the rest of your body. Knowing how well your blood performs this vital task can help you understand your overall wellness.

Blood Oxygen Monitor Pi

The majority of people have a blood oxygen level of 95 - 100%. However, some people live a normal life with blood oxygen levels below 95%. Slightly lower values while sleeping are expected, and some users might experience values below 95%.

How to use the Blood Oxygen app

Make sure that you meet the below requirements and follow the steps to set up the Blood Oxygen app.

Here's what you need

  • Make sure that the Blood Oxygen app is available in your country or region. You will be able to see this during the setup process.
  • Update your iPhone 6s or later to the latest version of iOS.
  • Update your Apple Watch Series 6 to the latest version of watchOS.*
  • The Blood Oxygen app is not available for use by people under 18 years old. You can confirm or set up your age in your Health Profile.

*The Blood Oxygen app is not available if you set up your Apple Watch with Family Setup.

Set up the Blood Oxygen app and background readings

  1. On your iPhone, open the Health app.
  2. Follow the onscreen steps. If you don't see a prompt to set up, tap the Browse tab, then tap Respiratory > Blood Oxygen > Set up Blood Oxygen.
  3. After you complete setup, open the Blood Oxygen app on your Apple Watch to measure your blood oxygen levels.

If you still don’t see the Blood Oxygen app on your Apple Watch, you can search the App Store on your Apple Watch for Blood Oxygen and download it.

The Blood Oxygen app is installed during the setup in the Health app. If you deleted the Blood Oxygen app, you can install it again from the App Store on your Apple Watch if you’ve completed the Blood Oxygen app setup.

How to take a blood oxygen measurement

You can take a blood oxygen measurement at any time with the Blood Oxygen app.

  1. Make sure that your Apple Watch is snug but comfortable on your wrist.
  2. Open the Blood Oxygen app on your Apple Watch.
  3. Stay still, and make sure your wrist is flat with the Apple Watch facing up.
  4. Tap Start, then keep your arm steady for 15 seconds.
  5. Wait. The measurement takes 15 seconds. At the end of the measurement, you will receive the results.
  6. Tap Done.

How to get the best results

  1. Rest your arms on a table or in your lap while you take a measurement. Keep your wrist and palm down and flat, and hold as still as you can.
  2. Make sure that your Apple Watch isn’t loose on your wrist. The band should be snug but comfortable, and the back of your Apple Watch needs to be touching your wrist.
  3. Make sure that the back of your Apple Watch is flush with the top of your wrist. If your wrist bones interfere with this, move your watch 1 to 2 inches up your arm away from your wrist bone.

Additional factors

Even under ideal conditions, your Apple Watch may not be able to get a reliable blood oxygen measurement every time. For a small percentage of users, various factors may make it impossible to get any blood oxygen measurement.

  • Skin perfusion (or how much blood flows through your skin) can impact measurements. Skin perfusion varies significantly from person to person and can also be impacted by the environment. If you are out in the cold, for example, the skin perfusion in your wrist might be too low for the sensor to work with the Blood Oxygen app to get a measurement.
  • Permanent or temporary changes to your skin, such as some tattoos, can also impact performance. The ink, pattern, and saturation of some tattoos can block light from the sensor, making it difficult for the Blood Oxygen app to get a measurement.
  • Motion is another factor that can affect your ability to get successful background or on-demand measurements. Certain postures, such as arms hanging by your side or fingers in a fist position will also result in unsuccessful measurements.
  • If your heart rate is too high (above 150 bpm) while at rest, you won't be able to get a successful blood oxygen measurement.

About background measurements

The Blood Oxygen app on your Apple Watch will occasionally measure your blood oxygen levels if background measurements are on. This will usually happen when you are not moving. Depending on how active you are, the number of readings collected each day and the time between these readings will vary. Blood oxygen measurements use a bright red light that shines against your wrist, so it may be more visible in dark environments. If you find the light distracting, you can turn off background measurements.

  1. Open the Settings app on your Apple Watch.
  2. Tap Blood Oxygen, then turn off In Sleep Mode and In Theater Mode.

Blood oxygen measurements only occur during sleep if the Track Sleep with Apple Watch setting is turned on.

How the Blood Oxygen app works

In Apple Watch Series 6, the optical heart sensor has been redesigned to add blood oxygen measurement capabilities. During a blood oxygen measurement, the back crystal shines red and green LEDs and infrared light onto your wrist. Photodiodes then measure the amount of light reflected back.

Blood Oxygen Monitor Finger

Advanced algorithms use this data to calculate the color of your blood. The color determines your blood oxygen level — bright red blood has more oxygen, while dark red blood has less.

View your Health information

All blood oxygen measurements, whether on-demand or in the background, are saved in the Health app on your iPhone.

  1. Open the Health app.
  2. Tap the Browse tab, then tap Respiratory > Blood Oxygen.

You can also filter and view measurements taken only while sleeping or in a high-elevation environment.

Best Blood Oxygen Monitor Watch

Things you should know

  • Blood Oxygen app measurements are not intended for medical use, including self-diagnosis or consultation with a doctor, and are only designed for general fitness and wellness purposes.
  • The Blood Oxygen app is designed for users who are at least 18 years old.

Learn more