Pulse Oximetry: Uses, Readings, and Choosing a Fingertip Oximeter

Pulse oximetry, a non-invasive and painless test, is used extensively in healthcare settings and, increasingly, at home. It offers invaluable insights into a person's blood oxygen levels, which is critical in various health situations. Let’s review the importance of a pulse oximeter and how to find the perfect fingertip oximeter for home monitoring.

Fingertip Oximeter Device

What is a Pulse Oximeter?

A pulse oximeter is a small, clip-like device that measures the oxygen saturation level in your blood. It is a non-invasive tool that attaches painlessly to your fingertip to gauge the amount of oxygen in your blood. It uses light absorption to determine the oxygen saturation of your blood.

Inside the device are two light sources, usually LEDs – one red and one infrared. These lights shine through your fingertip and hit a photodetector on the other side, which measures how much light is coming through. Oxygen-rich hemoglobin absorbs more infrared light and allows more red light to pass through. In contrast, oxygen-poor hemoglobin absorbs more red light and allows more infrared light to pass. By comparing the intensities of these two lights, the device calculates the percentage of oxygenated hemoglobin in your blood – a measurement known as SpO2.

The Purpose of a Pulse Oximeter and Its Uses

A pulse oximeter is primarily used to monitor the oxygen saturation of a patient's blood and pulse rates. This is crucial for individuals with conditions that may affect oxygen saturation. For instance, patients with chronic obstructive pulmonary disease (COPD), asthma, pneumonia, lung cancer, anemia, heart attack or heart failure, congenital heart defects, and COVID-19 might require regular monitoring of their blood oxygen levels.

Outside of healthcare settings, pulse oximeters are also used in various situations where oxygen levels might decrease, such as at high altitudes during mountain climbing or in airplanes. Athletes, especially those involved in endurance events like marathons, may use pulse oximeters to monitor their oxygen levels and improve performance.

The Importance of Your Blood Oxygen Levels

The oxygen that we breathe in travels from our lungs to every other part of our body through our blood. Oxygen is essential for the functioning of cells, tissues, and organs. Without sufficient oxygen, these structures may not function correctly, and severe hypoxia (low oxygen levels) can lead to organ damage and can be life-threatening.

Under normal circumstances, a healthy person should have an oxygen saturation level of 95% or higher. If the level drops below 90%, it is usually considered low and could indicate a medical emergency.

The Many Types of Pulse Oximeters

Fingertip Pulse Oximeters

These are the most common type and are convenient for home use. They are small, portable, and easy to use. You simply clip it onto your finger, and it provides a reading within seconds.

Handheld Pulse Oximeters

These are typically used in healthcare settings. They have a probe that can be attached to the finger, toe, or earlobe and connected to a handheld device that displays the readings.

Wrist-worn Pulse Oximeters

These are ideal for continuous monitoring, especially overnight. They are often used to diagnose conditions like sleep apnea.

Steps for Taking a Reading with a Pulse Oximeter

  1. Insert your finger into the device: The device usually has a hinge that opens and allows you to insert your finger. Ensure that your finger is clean and free from nail polish or artificial nails, which may affect the reading.
  2. Wait for the device to turn on: Some devices turn on automatically when you insert your finger, while others may require you to press a button.
  3. Remain still: Movement can disrupt the reading, so try to stay as still as possible.
  4. Wait for the reading: It usually takes a few seconds for the device to display the reading. Most devices will display both your oxygen saturation and pulse rate.

A Guide to Pulse Oximeter Readings

When you use a pulse oximeter, you'll typically see two numbers on the screen. One represents your oxygen saturation (SpO2), and the other is your pulse rate.

SpO2 Reading

A normal SpO2 reading is typically between 95% and 100%. If your reading is below 95%, it may be cause for concern, and you should consult a healthcare provider. A reading below 90% is considered low and requires immediate medical attention.

Pulse Rate

A normal resting heart rate for adults ranges from 60 to 100 beats per minute (BPM). Athletes and people who are very fit may have a resting heart rate below 60 BPM.

What to Look for in a Pulse Oximeter


Look for a device that promises an accuracy within 2%. The accuracy is usually listed in the product's specifications.

Ease of Use

Choose a device that is simple to use, especially if you're using it at home. Fingertip models are often the most straightforward.


A good pulse oximeter should have a clear and easily readable display. Some devices also offer adjustable brightness, which can be helpful for reading in different lighting conditions.

Battery Life

If you need to use the device regularly or for extended periods, consider its battery life.


The cost of pulse oximeters can vary. While some high-end models come with additional features like Bluetooth connectivity, a basic model should suffice for home use.

Shop for a Fingertip Oximeter Online at BIOS Medical

BIOS Medical has a range of fingertip oximeters that are accurate, user-friendly, and durable. Shopping with us gives you the advantage of detailed product descriptions, easy comparisons, and competitive prices, all from the comfort of your home. Whether you need a pulse oximeter for medical reasons or to monitor your health during high-intensity activities, you'll find a suitable device at BIOS Medical. Shop our selection of fingertip oximeters online or contact us for help.

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