What You Need to Know About Pulse Oximeter | Buying Guide

If you’ve come this far, it’s because you need a pulse oximeter. You may want to monitor your oxygen levels during training or during a mountain excursion. You may also be a patient with respiratory disease or even health care professional. The following paragraphs will resolve all your doubts about this product.

A pulse oximeter is a small device that measures oxygen saturation in your blood. It is shaped like a tweezer and can be placed on any finger. 


What exactly is a pulse oximeter?

pulse oximeter

A pulse oximeter is a small device that measures oxygen saturation in your blood. That is, this device estimates the number of oxygen molecules that our red blood cells carry. This measurement is critical in the field of health, as it allows us to know if our tissues are oxygenating (if they are “breathing”) properly. The example of the best-known pulse oximeter is the typical “clamp” placed on almost any finger. It is a non-invasive method that uses infrared light waves reflected in the blood and is again “captured” by the apparatus. This system makes a fairly accurate estimate of oxygen levels in the blood.

Pulse oximeters can also measure heart rate, allowing them to detect pulse disorders such as tachycardia. The most modern models have sensors that are placed on the forehead, in the people of the ear or around the wrist. The use of the latter is usually restricted to the hospital area (1, 2).


I have a respiratory disease. Can a pulse oximeter help me?

The use of the pulse oximeter is not limited to the hospital. Other health-oriented services, such as dentists, can use these devices to ensure their customers’ well-being. If we have a chronic respiratory type disease, we can benefit from the additional vigilance that oximeters will provide us. One of the dangers of chronic respiratory diseases is its impact on blood oxygenation. If our lungs have an obstruction of air passage (such as asthma or Chronic Obstructive Pulmonary Disease), our blood’s oxygen content will be reduced. This situation will be reflected in the pulse oximeter results.

If the oxygen saturation that marks our pulse oximeter drops below 95%, watch out! This value is the alarm signal indicating that the oxygenation of our tissues is insufficient. At first, this situation will affect our mental and physical performance. Left to its free evolution, poor oxygenation could endanger our lives.

However, don’t get carried away with fear. Most respiratory diseases (asthma, allergies or rhinitis) won’t jeopardize the oxygenation of our blood. In the case of a serious illness, our doctor could advise us to purchase a pulse oximeter to monitor our oxygenation and go to the ER if it falls below a certain value (2, 3).


I’m an athlete. Should I invest in a pulse oximeter?

In recent times, pulse oximeters have become fashionable among athletes, as they allow us to evaluate how exercise is affecting the oxygenation of our body. These devices will also monitor our heart rate, another important parameter that we must take into account during our workouts. If we are high athletes (such as mountaineers or climbers), a pulse oximeter could save our lives. The body’s difficulty in capturing oxygen from the atmosphere increases as the height at which we find ourselves increases. Using a pulse oximeter during these activities will help us know if we can continue our journey or go back.

Also, athletes suffering from chronic respiratory diseases (asthma, emphysema or chronic bronchitis, among others) may benefit from the purchase of a pulse oximeter. By carrying this device with them during sports practice, they can prey to any setbacks arising from their pathology and ask for help quickly.

A good cut-off point to start worrying about our oxygen saturation during sports practice is 95%. Below this value, we should stop and rest for a few minutes. If we do not manage to “go back” our oxygen saturation, the wisest option is to interrupt our activity and seek medical help (4, 5).


I’m a student in the Health Sciences. Should I buy a pulse oximeter?

A pulse oximeter is an invaluable tool for a student in Nursing, Physiotherapy, or Medicine. With a “pulse” in your robe pockets, you’ll be able to do more complete tests on patients. Unfortunately, the price of these devices can be too high an investment for a student’s pockets. Depending on the hospital where you do your internship, your superiors may lend you their own pulse oximeter. However, sooner or later, you’ll have to get hold of your own “pulse”. If you choose a good quality model, you can continue to use it even during your professional activity. To keep it from missing, choose a model that allows you to hang it around your neck.

Wrist oximeters, similar to a wristwatch and with the sensor on your finger, are used in sleep apnea patients. 


How is the pulse oximeter used?

  1. This non-invasive method for measuring blood oxygen saturation (SpO2) is carried out very easily. However, you should consider several guidelines for the measurement to be carried out correctly, as detecting levels below those indicated by medical equipment can become vital (3, 6). First, you need to clean the sensor with cotton or similar.
  2. Before placing the oximeter, remember that the nails must be clean without traces of enamel so that the measurement does not lead to wrong. You mustn’t move.
  3. Do not expose the oximeter to light, natural or artificial, just before reading the result.
  4. Make sure your hands aren’t too cold. If so, rub them until they reach an adequate body temperature.
  5. Place the device on your finger to measure at nail height.
  6. Wait a few seconds until you get the oxygen saturation reading.


What can affect the operation of my pulse oximeter?

  • Despite following the instructions above, some conditions could cause your pulse oximeter reading not to be as accurate as it should be. In that case, you should see a health care professional perform a measurement using another method (such as a gasometry). Problems that may interfere with pulse oximeter operation are (3): Excess light: The pulse oximeter sensor may fail if the measurement is performed in a very sunny environment or under too intense light.
  • Poor blood flow: If we have any conditions that affect the passage of blood through the fingers’ capillaries, the apparatus will be unable to give us an accurate measurement of our oxygen levels.
  • Movement: People with involuntary tremors (such as Parkinson’s) may have trouble getting an accurate reading, as constant movement decreases sensor accuracy.
  • Anemia or bleeding: If we do not have a sufficient amount of hemoglobin (anaemia) or have lost a lot of blood, the oximeter reading will not correspond to our blood’s actual oxygen values.
  • Poisoning: Certain gases, such as carbon monoxide released in fires, can bind to hemoglobin and expel oxygen. The pulse oximeter will detect this “intruder” gas like oxygen, giving us falsely normal oxygen saturation values. In that case, go to the ER even if your oximeter tells you “everything’s fine”!

Remember, if there is an oxygen reading, it gives us values less than 95%; we have to immediately consult with a medical team.


How should I interpret pulse oximeter results?

The interpretation of hospital pulse oximeters can be very complex. However, finger oximeters (especially those indicated for home use) are much simpler and can be easily used by most people. If we look at the screen of our “pulse”, we will see the following abbreviations (3):%SpO2: You can also find it with the acronym SpO2%, SpO2 or any similar variant. This “hieroglyph” is short for peripheral oxygen saturation, i.e. peripheral oxygen saturation. It is the value that determines whether the oxygenation of our blood is within healthy levels.


Bpm: In this case, this abbreviation comes from the English pulse rate beats per minute, i.e. the pulse measured in beats per minute. This value should be maintained between 60 and 100 beats per minute.

HR: Heart rate. It is the same parameter as PRbpm.

Your pulse oximeter may also show other results, such as a “wave” at the bottom of the screen (indicates blood flow and should look well defined, with regular ups and downs) or the acronym PI. The latter indicates the intensity of the pulse on the chosen finger. The higher the IP, the more accurate our measurement will be. Fortunately, the pulse oximeter is easy to interpret.


Buying Guide For Pulse Oximeter

Buying Guide For Pulse Oximeter

Before buying a finger pulse oximeter, you should consider several parameters that will make your decision easier. Before purchasing one, we advise you to consider the following features so that your purchase is a success.


Most oximeters have a standard size of 0.8 cm x 2.5 cm. However, to not make a mistake in choosing the size, we advise you to measure your finger from the tip of the nail to the bottom of the yolk. With this measure, you will be able to get the oximeter measurements right and not get any surprises after purchase.

If the pulse oximeter is to be used in different people (for example, in patients you take care of in your practices), try to choose a size that corresponds to the population you will serve (pediatric or adult). And don’t forget to choose a model with a strap to tie around your neck if you’re a little forgetful!

People with breathing problems mainly use finger pulse oximeters. 



It is true that today, all oximeters are up to date in terms of technology. However, you can rate those that offer you added features, such as signals that tell you if the test can’t be performed correctly (for example, by offering you THE VALUES). In this way, you will be completely sure of the veracity of the data.



Are you going to use the device continuously or only at specific times?. In this regard, you should evaluate whether you prefer the use of batteries or battery. Battery oximeters can be a good option if you’re travelling or hiking to undisposed areas (remember to bring disposed batteries!). Battery -pulses are a good option if you can recharge them daily.


Screen and data

We recommend that you look for a large screen, easy-to-read oximeter. Some offer records of previous tests, comparisons, and follow-ups. Don’t buy a very sophisticated one if you think such a reading can complicate your life. You can always resort to pointing the reading at a piece of paper and comparing the data yourself.

If you’re going to use it in low-light conditions (for example, during night workouts or in the emergency room), choose models that can modulate its brightness. The tech-enablers are recommended to choose a Bluetooth-connected oximeter capable of sending the results directly to the mobile phone.

Bob PageExpert in health education. Director of Edutainment Consulting and Seminars (USA)

“I think it was in 1986 that I first came across that new technology called “pulse oximeter.” (…) I thought it was amazing that you could tell me when to intubate a patient!”


Notice of desaturation

Note that there are oximeters that warn the user when there are low saturation levels, using a normally sound signal. Remember that a below-normal oxygen value will require seeking professional help. The most basic (and economical) oximeters do not usually include this function.

After-sales technical services These appliances usually need to be reviewed and recalibrated approximately every two years. Therefore, we advise you to look at whether the manufacturer offers this service or not. It’s also good to check if a recognized institution has validated your oximeter.

Athlete oximeters or pulse oximeters also include other features, such as heart rate control. 



On the market, there are a wide variety of finger pulse oximeters. You can find them for about 20 euros. However, it would help if you kept in mind that such low-cost devices may lose calibration faster. Those who incorporate more features have a longer service life, and better quality can get you out for more than 50 euros.



A pulse oximeter is a device that allows you to measure the blood saturation level (SpO2) painlessly. This useful device has gained a lot of popularity among patients with respiratory diseases, athletes, and heights lovers. Health Sciences students can count on him to get the most out of his practices.

The “pincer” oximeter will accompany us in our day-to-day life, helping us to control our oxygenation or to ensure the well-being of our patients and relatives. If you are using it at home, remember that this appliance will never replace personalized medical care. And you, where are you going to take your “pulse” today?

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Dr. Med. Raoul Hasert is a specialist in dermatology and venereology. He is a senior physician in Praxisklinik Dr. Hasert.

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