SpO2 and BP are both vital health measurements, but they represent different aspects of your body's functioning. SpO2, or peripheral capillary oxygen saturation, indicates the percentage of hemoglobin in your blood that is carrying oxygen, while BP, or blood pressure, measures the force of blood against your artery walls.
Understanding SpO2
What SpO2 Measures
SpO2 is a crucial indicator of how well oxygen is being transported throughout your body. According to reference [16], it reflects the ratio between hemoglobin carrying oxygen and the total amount of hemoglobin in the blood.
- Hemoglobin is a protein in your red blood cells that carries oxygen from your lungs to the rest of your body.
- A higher SpO2 level means that more hemoglobin is carrying oxygen, indicating better oxygenation of your tissues.
Normal SpO2 Levels
Normal SpO2 values typically range from 96% to 98% [16], and can sometimes reach up to 100%. A reading below 90% is generally considered low and may require medical attention.
How SpO2 is Measured
SpO2 is most commonly measured using a pulse oximeter, a small device that clips onto your fingertip. The measurement principle is similar to that with a smartphone [16].
Understanding Blood Pressure (BP)
What BP Measures
Blood pressure measures the force of your blood pushing against the walls of your arteries. It's a key indicator of cardiovascular health. It consists of two numbers:
- Systolic Pressure: The pressure when your heart beats and pumps blood out.
- Diastolic Pressure: The pressure when your heart rests between beats.
Blood pressure is typically expressed as two numbers, such as 120/80 mmHg (millimeters of mercury).
Normal BP Levels
Normal blood pressure generally falls around 120/80 mmHg, but this can vary based on age, health, and other factors. High or low blood pressure can be indicative of health concerns.
How BP is Measured
Blood pressure is measured using an inflatable cuff placed around your arm. The cuff inflates to restrict blood flow and then releases slowly, taking readings as the pressure changes.
Key Differences:
| Feature | SpO2 | Blood Pressure (BP) |
|---|---|---|
| What it is | Oxygen saturation in the blood | Force of blood against artery walls |
| What it measures | Percentage of hemoglobin carrying oxygen | Systolic and diastolic pressures |
| Normal range | 96-98% (can reach up to 100%) [16] | Typically around 120/80 mmHg, but varies based on age and health. |
| Measurement | Pulse oximeter (fingertip device) | Sphygmomanometer (inflatable cuff) |
Conclusion
In summary, while both SpO2 and BP are vital signs, they measure different aspects of your health. SpO2 indicates how effectively oxygen is being transported in your blood, while BP measures the pressure of your blood against your artery walls. Monitoring both provides a more comprehensive picture of your overall health.
