SpO2, or saturation of peripheral oxygen, indicates the percentage of oxygen carried in your blood. This measurement reflects how effectively oxygen is transported throughout your body, offering insights into respiratory health and overall well-being.
Understanding Oxygen Saturation
Oxygen is essential for various bodily functions, especially cellular energy production. Cells convert nutrients into adenosine triphosphate (ATP), their primary energy source. Without sufficient oxygen, cells cannot produce enough energy, impacting organs like the brain and heart.
Red blood cells transport oxygen from the lungs to the body’s tissues. Hemoglobin within these cells binds to oxygen, enabling its efficient transport. Each hemoglobin molecule can carry up to four oxygen molecules. Upon reaching tissues, red blood cells release oxygen, which diffuses into cells for metabolic use.
How SpO2 is Measured
SpO2 is measured using a pulse oximeter, a small, non-invasive device clipped onto a fingertip, earlobe, or toe. This device emits red and infrared light through the tissue. Oxygenated and deoxygenated hemoglobin absorb these light wavelengths differently.
The pulse oximeter detects the light that passes through the tissue. By analyzing the ratio of absorbed red and infrared light, the device calculates the percentage of hemoglobin saturated with oxygen. This measurement is displayed as a percentage.
Several factors can influence the accuracy of pulse oximeter readings. These include poor circulation, movement, nail polish, or artificial fingernails. Skin pigmentation and smoking can also affect accuracy, with studies indicating inaccuracies for darker skin tones or smokers.
Interpreting Your SpO2 Levels
For most healthy individuals, a normal SpO2 reading ranges between 95% and 100%. Readings within this range indicate efficient oxygen delivery to tissues. Individuals with chronic lung conditions might have naturally lower acceptable levels, which their healthcare provider can specify.
A lower-than-normal SpO2 reading, below 92%, may indicate hypoxemia, a condition of low blood oxygen. Symptoms can include shortness of breath, a rapid heartbeat, confusion, or a bluish tint to the skin, lips, or fingernails.
Seek medical attention if your SpO2 level consistently falls below 92%, especially if accompanied by symptoms like severe shortness of breath or changes in mental state. If the reading drops to 88% or lower, immediate medical care is necessary. Interpret SpO2 readings in context with other symptoms and existing medical conditions.