As a medical professional, I can tell you that an oxygen level of 84% is indeed a cause for concern. Normally, a healthy individual's oxygen saturation level should be between 95% and 100%. Oxygen levels between 92% and 88% are considered safe for someone with moderate to severe Chronic Obstructive Pulmonary Disease (COPD), but once it drops below 88%, it becomes dangerous. At 84% or lower, it's advisable to seek immediate medical attention, as levels around 80% and below are considered dangerous for your vital organs and require immediate treatment. read more >>

Anything between 92% and 88%, is still considered safe and average for someone with moderate to severe COPD. Below 88% becomes dangerous, and when it dips to 84% or below, it's time to go to the hospital. Around 80% and lower is dangerous for your vital organs, so you should be treated right away.read more >>