A pulse oximeter is a small, non-invasive device used to monitor the oxygen saturation level in a person’s blood, known as SpO2. This tool gained significant attention during the COVID-19 pandemic as a means for individuals to track their oxygen levels at home. Understanding how to interpret these readings, along with recognizing other concerning symptoms, is important for knowing when to seek medical attention.
How Pulse Oximeters Work
A pulse oximeter functions by emitting light through a fingertip, using two light beams, red and infrared, which pass through the blood. Oxygenated and deoxygenated hemoglobin absorb these wavelengths differently. By measuring light absorption, the oximeter calculates the percentage of hemoglobin carrying oxygen, providing an SpO2 reading. This reading indicates how well the lungs supply oxygen to the blood, with a normal range for healthy individuals being 95% to 100%. These devices are easy to use at home, offering a quick and painless way to estimate blood oxygen levels.
Understanding COVID-19 Pulse Oximeter Readings
For COVID-19, pulse oximeter readings provide valuable information about respiratory function. A reading consistently at or above 90-92% is generally acceptable for home monitoring. An SpO2 reading between 90% and 94% may indicate mild hypoxemia, or low blood oxygen, warranting medical evaluation. If SpO2 drops below 90%, it is considered clinically significant hypoxemia and requires immediate medical attention, as this threshold can increase the risk of severe complications and even death. For accurate measurements, rest for at least five minutes, warm your hand, and remove nail polish before taking a reading.
Additional COVID-19 Symptoms Requiring Attention
While pulse oximeter readings are useful, they are not the only factor for assessing COVID-19 severity. Some individuals experience “silent hypoxemia,” where oxygen levels are dangerously low without noticeable shortness of breath. This makes monitoring for other symptoms important. Severe symptoms, even with a normal SpO2 reading, necessitate immediate medical attention. These include persistent chest pain or pressure, which can indicate heart or lung complications, new confusion or inability to wake or stay awake, and pale, gray, or blue-colored skin, lips, or nail beds (cyanosis), which signals severely low oxygen levels.
When to Seek Immediate Medical Help
If your SpO2 level consistently drops below 90%, seek immediate medical help, as this low oxygen saturation is a medical emergency. Beyond SpO2 readings, any severe symptoms also warrant prompt action. These include significant difficulty breathing or feeling like you cannot catch your breath, persistent chest pain or pressure, new confusion, or an inability to wake or stay awake. If you notice bluish discoloration of your lips, face, or nail beds, call emergency services immediately. In such situations, call 911 or your local emergency number, or go to the nearest emergency room.