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How To Use Oximeters Properly?

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How To Use Oximeters Properly?

4 min read


In today’s world, there are an array of health problems that are the primary drivers for the development of health monitoring technologies. This article will contribute some information about the oximeters.

Medically reviewed by

Dr. Sugreev Singh

Published At February 21, 2022
Reviewed AtApril 13, 2024


COVID-19 is taking its toll on the whole world, causing deaths, illnesses, and economic despair. There are a number of deaths every day due to a lack of oxygen. Monitoring oxygen saturation levels is crucial in people with breathing ailments, but how to keep a check on our oxygen saturation levels? Pulse oximeters do the job. These are the most promising wearable health monitoring devices. It is a non-invasive way of measuring blood oxygen levels. This device was invented by Karl Matthes in 1935. Since their development, these pulse oximeters have undergone various changes and modifications.

What Is Pulse Oximetry?

Pulse oximetry is a test or a procedure that is used to measure the oxygen saturation (oxygen level) of the blood. It measures the oxygen that is sent to different parts of the body from the heart. It is a painless and non-invasive measuring procedure.

What Is Oxygen Saturation?

The red blood cells (RBC) contain hemoglobin that carries oxygen. When hemoglobin is carrying oxygen, it is described as saturated with oxygen.

How Are Pulse Oximeters Placed?

The pulse oximeter is an electronic device that measures the oxygen saturation in the blood. A clip-on device called a probe is attached to the finger or to the ear lobe.

How Does a Pulse Oximeter Work?

The pulse oximeters are composed of a sensor and a monitor with a display. Pulse oximeters have light-emitting diodes which shine two types of red light through the tissue. The sensor on the other side of the tissue picks up the light that is transferred through the tissues. The pulse oximeters can determine which of the hemoglobin is in arterial blood and can determine the SpO2 of the arterial blood in the circulation.

When Do I Need a Pulse Oximeter?

Pulse oximeters are used to measure if there is sufficient oxygen in the blood. It is used

  • During surgery and after surgery.

  • When people have difficulty in breathing and in assessing if the person needs a ventilator to help with the breathing.

  • For people who have sleep apnea.

The pulse oximeter is also used for people who have any health illness that affects the blood oxygen levels, like,

Pulse oximeters can also be recommended for any other health conditions by healthcare professional. Consider purchasing a pulse oximeter under the guidance of a doctor.

How to Use Pulse Oximeters Properly?

  • The probe should be attached to the finger correctly to ensure the oximeter works correctly. These probes are fragile, so they need to be handled with caution.

  • The probe has to be well-positioned on the finger. The finger should fit well and make sure the probe is not too tight as it can constrict the blood circulation, or if it is loose, it may fall off and let the other light in.

  • Do not move the finger to which the pulse oximeter is attached.

  • Wait a few seconds until the reading stops changing and displays one steady number.

  • Note down the values with the date and time on which oxygen level was measured so that one can keep track of the changes of the values and can report it to the healthcare professional.

Ear Probes:

Ear probes are attached to the ear lobe. In small children, ear probes can also be used on the cheeks.

When Can the Readings From the Pulse Oximeter Be Not Accurate?

  • When the patient is wearing any nail paint or henna.

How Does it Interfere With the Readings of the Pulse Oximeter?

The color can absorb the light that is emitted by the oximeter and interfere with the detection of oxygenated hemoglobin. The oximeter may pick the pulse, but it will not be able to measure the oxygen saturation level as the pigment will block the signal. So it is better to remove the nail paint from the finger on which the device is going to be clipped on.

  • When there is a bright light, such as sunlight falling on the probe, it can interfere with the light detector. This can lead to inaccurate readings.

  • Patients who have inhaled smoke or fire can have a high amount of hemoglobin combined with carbon monoxide. Most of the oximeters cannot detect this and can tend to exaggerate the oxygen saturation level.

What Precautions Should Be Taken When Checking the Oxygen Saturation Levels at Home?

  • When measuring the oxygen saturation levels, check if the oxygen levels are lower than the previous recordings, and if the measurements are decreasing day by day, just do not rely only on the pulse oximeter but do contact a healthcare professional to assess the patient's health condition.

  • While monitoring the oxygen saturation levels, do look for the other signs and symptoms like:

If one notices these symptoms and if these symptoms are getting severe, then do contact a healthcare professional. Purchasing blood oxygen saturation monitor at home has helped individuals to avoid complications due to low oxygen saturation levels.

What Are the Types of Pulse Oximeters?

There are two categories of pulse oximeters,

  • Prescription Use:

These pulse oximeters can be bought only with a prescription. These pulse oximeters are reviewed by the FDA (Food and Drug Administration). They are often used in doctor’s offices hospitals, and sometimes they can be prescribed for home use also.

  • Over-the-counter Oximeters:

These pulse oximeters are sold directly in stores or online. This includes smartphone apps and smartwatches. This has not undergone FDA approval, so it cannot be used for medical purposes.

How Is Pulse Oximeters Useful in This COVID-19 Situation?

If one suspect they have COVID-19, do contact the healthcare professional. Pulse oximeters do help in the diagnosis of COVID-19. During COVID, the oxygen level may be low, so these pulse oximeters will help to measure the oxygen saturation levels.

What Is the Normal Oxygen Saturation Level?

Oxygen saturation values are between 95 % and 100 % for most healthy individuals, but they can be lower for individuals with lung problems. Oxygen saturation levels are slightly lower in those individuals living in higher altitude areas.


In this pandemic crisis, everyone wants to make sure they are healthy, so they try to buy some non-recognized pulse oximeters over the stores and online, which is not even approved by authorities like the FDA. So just do not rely on pulse oximeters. Do contact the healthcare professional if they experience any of the symptoms when it is in a mild state. Ignoring it or home diagnosis can lead to serious adverse effects.

Frequently Asked Questions


What Is the Correct Technique to Use a Pulse Oximeter?

The majority of pulse oximeters carry usage instructions.  The basic steps to use a pulse oximeter are:
- Put the batteries in the pulse oximeter after removing it from the packaging.
- The index, middle, or ring finger should be clipped with the pulse oximeter.
- Press the button on the device to start the pulse oximeter. Do not move the hand.
- Note the time, oxygen saturation in blood, and pulse rate.


What Is the Average Time to Keep a Finger in an Oximeter?

Keep the pulse oximeter in position for at least a minute. Note the highest result after the reading has stayed the same for five seconds. The readings for the heart rate and oxygen level should be identified carefully.


Which Finger Is Good for an Oximeter?

The right middle finger's measurement of the highest oxygen saturation level (98.2 % 1.2) was statistically significant when compared to the right little finger and the left middle finger. The right thumb provided the second-highest average oxygen saturation reading, which was statistically significant only when compared to the left middle finger. The right thumb and middle finger on the right hand are assumed to have the most accurate measurements of arterial oxygen saturation.


What Is the Normal Oxygen Level by Age?

For adults and children, oxygen saturation levels between 95 % and 100% are considered normal (below 95 % is regarded as problematic). Oxygen saturation levels in people over 70 may be closer to 95 %. Both adults and children should have oxygen saturation levels (SpO2) between 95 % and 100 %.


What Is Normal Pulse Oximeter Reading?

95 % or more oxygen saturation is considered normal. Compared to younger people, it will be closer to 99 % in elderly adults, who are closer to 95 %. Both adults and children are deemed to have oxygen saturation levels (SpO2) between 95 and 100 percent (below 95% is considered abnormal). Oxygen levels in those over 70 may be closer to 95 %. Normal oxygen saturation levels (SpO2) range from 95 to 100 % for adults and children.


How Many Times a Day to Use an Oximeter?

According to the studies, doctors recommend using an oximeter at least two times daily. Measure the oxygen level twice daily, both at rest and when a person is at rest.


Can a Pulse Oximeter Detect Shortness of Breath?

Yes, the pulse oximeter can detect shortness of breath. It helps assess how seriously the lung is compromised. The examination can be performed as a single spot measurement. Additionally, it can monitor the oxygen levels throughout time, such as while sleeping or exercising - such as walking.


Why Does My Oximeter Show Different Readings?

The oximeter could not give a reliable reading if the fingers were cold, wearing nail polish, or moving around. It is important to remove any nail paint before using an oximeter, avoid using it on cold fingers, and sit upright. The middle finger is the best to use as an oximeter.


Does Cough Reduce Oxygen Levels?

Yes, the amount of oxygen that may enter the bloodstream and move throughout the body is limited by frequent coughing and the resulting decrease in carbon dioxide levels.


Are Home Oximeters Accurate?

The typical accuracy rate for prescription oximeters is 4 % above or below a reading. As a result, a 92 % oxygen level could potentially be 88 % or 96 % higher. Additionally, measurements from pulse oximeters are frequently most accurate when they are over 90 %.


Which Color Is the Most Affect Pulse Oximeter?

In the three studied pulse oximeters, dark skin pigmentation causes an overestimation of arterial oxygen saturation, particularly at low saturation. The best course of action at this time is to post a warning to this effect. Oximeter measurements for oxygen saturation were considerably lowered by nail lacquer in shades of black, blue, and green. Black showed an intermediate drop, whereas purple and red produced higher decreases.


Can an Oximeter Detect Irregular Heartbeat?

Heart rate can be measured using pulse oximetry equipment in resting and elevated states. It functions by monitoring the differences in light between each pulse and timing how long it takes between them. Some gadgets display the pulse rate as a number, a visual graph, or both, depending on the gadget. Individuals and medical experts can determine how quickly the heart beats and how much oxygen saturation is in the blood using the combined information. They help identify any potential health problems as a result.


Can Oximeters Detect Lung Damage?

Pulse oximetry can also assess how seriously someone's lungs are compromised. The examination can be performed as a single spot measurement. Additionally, it can monitor oxygen levels throughout time, such as while you are sleeping or exercising - such as walking.


What Is the Bottom Number on a Pulse Oximeter?

The blood oxygen level is shown at the top, and the heart rate is at the bottom. A pulse oximeter should be used three times a day.


Do Cold Hands Affect Oximeter Readings?

The blood vessels narrow due to the low temperatures, which limits blood flow and lowers oxygen levels. Your heart must pump harder than usual to circulate blood through the restricted arteries effectively. Your heart rate and blood pressure then increase as a result.
Source Article IclonSourcesSource Article Arrow
Dr. Sugreev Singh
Dr. Sugreev Singh

Internal Medicine


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