What is a Dangerous Pulse Oximetry Level?

You’ve probably heard of a pulse oximeter, or even had one clipped to your finger during a trip to the ER or hospital stay. It’s a small, painless device that measures your blood oxygen level. It gives you a number (often called a percentage) of how much oxygen is in your blood at any given time and also displays your heart rate. It can be a helpful tool in finding out if you need extra oxygen to get well from COVID-19 or other breathing problems.

A healthy blood oxygen level (also known as oxygen saturation) is typically between 95 and 100 percent, with a lower number being an indication of a low blood oxygen. If your reading is lower than that, it’s important to seek immediate medical attention.

Your blood oxygen levels are affected by a variety of factors. Some, like a cold or the flu, may cause your lungs to become inflamed and make it harder for you to breathe. Other conditions and diseases, like COPD or asthma, can also lower your oxygen level and lead to breathing complications.

If you have a chronic condition that affects your lungs or heart, you may be monitored by a pulse oximeter at home to check your blood oxygen levels regularly. Your doctor may give you a device to use or recommend a particular brand that is safe and effective for your needs.

You can purchase a pulse oximeter over-the-counter (OTC) to monitor your oxygen at home, but it’s best to speak with your physician before using one to decide if you are a candidate for self-monitoring and to find out how often to check it. You’ll want to look for changes or trends over time rather than a single, quick measurement.

Pulse oximeter accuracy is affected by many patient factors, such as skin pigmentation and age. Some recent research has shown that pulse oximeters are less accurate for patients with darker skin pigmentation than for those with lighter skin. These differences are not large, however, and are usually only noticeable at saturations below 80%.

In a recent study by researchers at Penn Medicine, a group of patients who had COVID-19 with mild symptoms were asked to track their oxygen levels at home using a simple pulse oximeter device. Compared to patients who did not monitor their oxygen, the group who used the device experienced similar recovery rates and was able to detect early signs of trouble, such as shortness of breath or confusion. This is an important finding because it shows that using a pulse oximeter can help identify those who are at risk of developing respiratory or cardiovascular complications and require treatment with extra oxygen at home or in the hospital. The results also support the need for a system that provides easy-to-understand information about oxygen levels to the public, so people can easily determine whether they need medical care. The study was published in the New England Journal of Medicine.