Normal Pulse Oximetry Ranges and How to Take a Reading

Medically reviewed by Jeffrey S. Lander, MDMedically reviewed by Jeffrey S. Lander, MD

Pulse oximetry is a quick and noninvasive test that measures the oxygen saturation level in your blood using a device called a pulse oximeter. It helps monitor how well oxygen is being delivered in the body.

Low oxygen levels can occur due to health conditions such as asthma, pneumonia, or chronic obstructive pulmonary disease (COPD). Pulse oximeters are frequently used in hospitals and clinics but can also be used at home.

Normal Ranges

Most people have a normal resting pulse oximetry reading for oxygen saturation (SpO2) between 95% and 100%. This shows that your blood has an appropriate amount of oxygen. People at higher altitudes may have slightly lower readings.

If your oxygen saturation level drops below 95%, it may suggest a potential issue with your lung or heart function. Levels below 92% are considered low and may require medical attention. You should seek immediate medical attention for a reading of 88% or lower.

The pulse oximeter (or pulse ox, for short) works by shining a light through the skin and determining the amount of oxygen based on how the light travels through the skin and blood vessels.

It's important to note that some factors, such as darker-pigmented skin and even the use of nail polish, can affect how the pulse oximeter reads oxygen levels. Other factors, such as being in high altitudes and incorrectly using the pulse oximeter, can sometimes interfere with normal readings.

How Medical Professionals Use Pulse Oximeters

Medical professionals frequently use pulse oximetry to assess a patient’s oxygen level quickly in many settings. In hospitals, it's commonly used in emergency rooms, operating rooms, and intensive care units to monitor patients, especially those with conditions affecting the heart and lungs.

Pulse oximeters help healthcare providers detect sudden drops in oxygen levels, which can indicate a serious issue such as respiratory failure or complications during surgery. By monitoring continuously in real time, healthcare providers can act immediately to provide interventions to help support healthy oxygenation.

In everyday medical practice, pulse oximetry is used during routine checkups for people who visit their provider’s office. It can help track how well treatments like inhalers or supplemental oxygen work. It is also helpful in assessing people with symptoms of COVID-19 or other infections that can affect lung function.

A pulse ox is a simple, noninvasive way to monitor oxygen levels in any healthcare setting.

When You May Want a Home Test

You may want to have a pulse oximeter at home if you have health conditions that affect your lungs or heart.  Conditions such as COPD, asthma, heart failure, or sleep apnea can cause your oxygen levels to decrease. Monitoring at home can allow you to track changes and respond quickly.

Many people also found home pulse oximeters useful during the COVID-19 pandemic, as the virus can cause low oxygen levels before other symptoms became worse.

If you experience frequent shortness of breath, fatigue, or other signs of low oxygen, having a pulse oximeter on hand can give you peace of mind by helping you check your levels without needing to visit a healthcare provider each time.

However, it's important to talk to your healthcare provider about how to use a pulse oximeter correctly and how to interpret your results correctly to ensure you're getting accurate information. You should also know when to contact your healthcare provider for low oxygen levels.

How to Take a Reading

Taking a reading with a pulse oximeter is simple. To begin, make sure your hands are warm, as cold fingers can affect the accuracy. Remove any fingernail polish or artificial nails.

Follow these steps:

• Turn on the pulse oximeter and place it on your fingertip, ideally the middle or index finger.

• Sit still and avoid moving while the device reads your oxygen levels and heart rate.

• The screen will display your oxygen saturation level (SpO2) and pulse rate within seconds.

• Ensure the reading is stable for 30 to 60 seconds before removing the device.

• If you get an unexpected result, try taking the reading again after a few minutes to ensure accuracy.

For the best results, always follow the manufacturer’s instructions and consult your healthcare provider if you’re unsure how to interpret the readings.

Understanding Your Reading

When interpreting the readings of a pulse oximeter, it’s important to understand what the numbers mean. The oxygen saturation level is shown on the device as SpO2. This reflects the percentage of oxygen in your blood.

A normal reading typically ranges from 95% to 100%. Levels below 92% are considered low and could indicate a more serious issue, so contact a healthcare provider. Seek immediate medical attention for a reading of 88% or lower.

Along with oxygen saturation, the pulse oximeter will display your heart rate, measured in beats per minute (BPM). The target number is based on age and can vary depending on your fitness level or whether you're resting or active.

While occasional changes in oxygen levels might be normal, consistently low readings or symptoms like shortness of breath, chest pain, or confusion should be discussed with a healthcare provider immediately.

Certain factors, such as poor circulation, wearing nail polish, being overweight, or having a dark skin tones, can affect accuracy and bias of the reading. If you notice unexpected results, take multiple readings and notify your healthcare provider.

What Happens Next

If your pulse oximeter consistently shows low readings, it’s important to notify your healthcare team. Low oxygen levels, known as hypoxemia, can indicate that your body isn’t getting enough oxygen.

If you’re experiencing symptoms like shortness of breath, confusion, or chest pain along with low readings, you should contact your healthcare provider right away or seek emergency treatment.

In some cases, supplemental oxygen or other treatments may be needed to increase your oxygen levels. Your healthcare provider may also order additional tests to investigate the cause of the low readings and develop a treatment plan.

Summary

Pulse oximetry is a quick, noninvasive test that measures the oxygen saturation levels in the blood, using a device called a pulse oximeter. It helps monitor how well oxygen is being delivered throughout the body. It is commonly used in hospitals, healthcare provider offices, and at home.

Normal oxygen saturation levels range from 95% to 100%, with levels below 92% signaling a potential medical issue. Factors like skin tone, nail polish, and device errors can affect accuracy of the pulse ox reading.

Home pulse oximeters can be useful for people with chronic conditions, but it’s essential to understand how to use and interpret the readings properly. Consistently low oxygen readings may require immediate medical attention or further evaluation by a healthcare provider.

Read the original article on Verywell Health.