However, this may not indicate adequate oxygenation because there are less hemoglobin to carry an adequate supply of oxygen for people who have anemia. Oxygen saturation may remain normal (e.g., 97% and higher) for people with anemia.Oxygen saturation levels may decrease slightly when a person is talking.With hypercapnia, it is difficult for the pulse oximeter to differentiate oxygen in the blood from carbon monoxide (caused by smoking). Smoking can influence the accuracy of pulse oximetry in which the the SpO2 is low or falsely high depending on whether hypercapnia is present.People who are obese and/or have conditions such as lung and cardiovascular diseases, emphysema, chronic obstructive pulmonary disease, congenital heart disease and sleep apnea tend to have lower oxygen saturation levels.Thus, it is important to understand both baseline readings and underlying physiology associated with certain conditions to interpret oxygen saturation levels and changes in these levels. It is important to note that the oxygen saturation level varies considerably based on a person’s state of health.
For example, someone older than 70 years of age may have an oxygen saturation level of about 95%, which is an acceptable level.
Older adults typically have lower oxygen saturation levels than younger adults. The normal oxygen saturation level is 97–100% (OER #1). What are Normal Oxygen Saturation Levels?