Your blood oxygen levelsometimes referred to as SpO2measures how much oxygen is circulating in your bloodstream.
There are many ways to measure blood oxygen, and options are increasing with wearable health devices like smartwatches.
Ideally, 100% of these blood cells carry oxygen, but this isn’t always the case.
Illustration by Zoe Hansen for Verywell Health
A normal range for your blood oxygen level is between 92% and 100%.
SpO2 readings can fluctuate based on activity, overall health, and other factors.
However, a drop into the low 90% range and below can becomedangerousquickly.
Many tissues in your body require a constant supply of oxygen to function.
Heart and brain tissue are very sensitive todecreases in blood oxygenlevels and display concerning symptoms when they lack oxygen.
You don’t necessarily need a blood oxygen reading when you have these symptoms.
In some cases, a lower target is appropriate.
These sensors can work almost anywhere, but a sensor placed on your finger is the most common method.
Generally speaking,pulse oximetersare accurate, but accuracy declines as your blood oxygen level drops.
As technology has improved, wearable devices that measure oxygen levels have become more popular.
Even smartwatches can help you track your oxygen level.
If you have COPD or other chronic pulmonary diseases, your blood oxygen targets may be lower.
Experts typically advise people withCOPDto maintain an oxygen level between 88% and 92%.
SpO2 and Sleep
When yousleep, your breathing slows.
Maintaining an oxygen level that is too high can be a problem for some conditions, like COPD.
You may also need oxygen for a short period as you recover from certain conditions.
In most cases, your healthcare provider will give you a target blood oxygen level to maintain.
Your home oxygen gear will have a dial to adjust the amount and flow of oxygen you receive.
It’s essential to take certain precautions if you use at-home oxygen.
Use caution around open flames, as oxygen is highly flammable.
Gas stoves, cigarette smoking, and other sources of open flames should be avoided.
Summary
Blood oxygen levels fluctuate with activity, sleep, and various health problems.
If your blood oxygen levels regularly drop below 92%, talk to your healthcare provider about possible causes.
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