This article explains what the ODI is and how it’s measured.
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What Is the ODI?
Drops in blood oxygen level are called desaturations.
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Still, your low daytime levels may lower if you have a sleep-related disorder.
Whether low daytime oxygen can predict desaturation at night is still being studied, however.
A drop below 80% is considered severely abnormal.
Generally, your oxygen levels will drop slightly during sleep.
This is because your respiratory rate and volume tend to be reduced when you’re sleeping.
Your ODI score is based on how much and how often your oxygen level drops during the test.
What Causes Worsened ODI?
During sleep, muscle tone diminishes a little.
This doesn’t have a noticeable or substantial effect on most people.
With OSA and other conditions that affect ODI, these drops are typically associated with apnea or hypopnea.
The ODI differs from theapnea-hypopnea index (AHI), which is another measurement.
The AHI also includes events that may cause arousal or awakenings from sleep without affecting oxygen levels.
Sleep Fragmentation
Sleep fragmentation (an interruption of sleep) can occur due to breathing issues.
It can happen with or without the associated desaturations.
Even when sleep fragmentation occurs without an effect on oxygen saturation, it can cause daytime sleepiness.
Other Causes
Other conditions can cause problems with breathing and/or oxygenation during sleep and affect your ODI.
Hypoxia and hypoxemia can be harmful to your body, especially if the problem is prolonged and recurrent.
Treatment
The treatment for ODI abnormalities during sleep depends on the cause.
Your ODI score is an assessment of how much and how often your oxygen level drops during the test.
Resolving sleep-disordered breathing may benefit both sleep quality and long-term health.
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