Is there a low, medium, or high range? What is the scale?

Each lab sets the level for what determines a positive result. A “high” result is not a range, but means that your level is above the level set by the lab. For example, if a lab has set a level of  1.0, anything above that is considered high (positive, detected). The number in your results should not be used to determine how immune or protected you are from reinfection. Talk to your healthcare provider for additional guidance on how to interpret your test results.