The level of oxygen in the blood is measured as a percentage. If the measurement shows 95%, it means that 95% of hemoglobin carries oxygen and 5% does not.
The level of oxygen saturation in the blood (SpO2) is one of the main indicators used to determine whether a patient needs to be given oxygen through a mask and whether they need artificial ventilation.
The healthy people's blood oxygen saturation level is 95%. At a level of less than 94%, the human condition is a concern, and at 90%, who suggests using an oxygen mask, since the tissues do not receive enough oxygen.
If the SpO2 level is below 90%, the risk of hypoxemia increases. This is a lack of oxygen in the blood.