A pulse oximeter is a small, non-invasive device that typically clips onto a finger and provides immediate readings of vital signs. The top number displayed on this device indicates your oxygen saturation.
Understanding Oxygen Saturation
The top number on a pulse oximeter represents your oxygen saturation, often abbreviated as SpO2. This measurement indicates the percentage of hemoglobin in your red blood cells that is currently carrying oxygen. Hemoglobin picks up oxygen in the lungs and delivers it throughout the body.
A healthy oxygen saturation level ensures that organs receive the necessary oxygen to function properly. The pulse oximeter achieves this by shining two wavelengths of light through the skin, measuring how much light is absorbed by oxygenated versus deoxygenated hemoglobin.
Interpreting Your Readings
For most healthy individuals, a normal oxygen saturation reading typically falls between 95% and 100% when measured at sea level. Readings within this range suggest that your blood is carrying an adequate amount of oxygen. However, for individuals with certain lung conditions, such as chronic obstructive pulmonary disease (COPD) or pneumonia, a slightly lower range might be considered acceptable by their healthcare provider.
A reading below 95% is generally considered low and is known as hypoxemia, indicating that there might not be enough oxygen circulating in the blood. When oxygen levels drop, it can affect how well your body’s tissues and organs function. Causes of low oxygen can stem from issues with breathing, reduced oxygen-carrying capacity of the blood, or problems with blood flow, such as those seen in lung conditions or heart abnormalities.
Readings above 100% are not physiologically possible for oxygen saturation measured by a pulse oximeter and usually suggest a device error or an issue with the reading. Several factors can influence the accuracy of a pulse oximeter reading, including the presence of nail polish or artificial nails, cold fingers, excessive movement, or even darker skin pigmentation. These factors can interfere with the light signals the device uses to calculate the reading.
When to Consult a Doctor
A pulse oximeter serves as a screening tool to monitor oxygen levels and should not replace professional medical advice or diagnosis. It offers a snapshot of your oxygen saturation at a given moment. If your oxygen saturation consistently reads below 92% for a healthy individual, it is advisable to contact a healthcare provider.
You should seek medical attention if low readings are accompanied by concerning symptoms such as severe shortness of breath, a rapid or irregular heartbeat, confusion, persistent coughing, or a bluish tint to your skin, lips, or fingernails. These symptoms suggest that your body may not be getting enough oxygen. Your healthcare provider can determine the underlying cause of any abnormal readings and recommend appropriate steps or further diagnostic tests.