Chris Kresser: Next question from Chi: “According to [the] NHS in the UK, the BUN test is the same as the urea test they offer. A reputable private lab, however, says this is not the case, and BUN is a completely different test than the urea test offered by the NHS.”
Yes. BUN is not urea. They are different tests. The example you provided there, Chi, I think can answer the question pretty well.