Asked by: Paul Leslie, by email
As a reliable replacement for conventional medicine, no. A severe ear infection can result in pus being discharged from the ear, which will smell quite nasty, but that isn’t actually the earwax itself and so perhaps doesn’t count.
Earwax, like many other bodily secretions, will show traces of certain non-biodegradable toxins in the body, such as heavy metals. But it’s an odd place to look and no more reliable than a simple blood test. There are also some rare metabolic disorders that affect earwax.
Alkaptonuria (which causes a build up of homogentisic acid) turns your earwax black, for example. However, since it also turns your urine dark brown, you would probably already know something was wrong.