With which you mean the process causes discomfort? Probably less so than being asthmatic and/or a host of other things, but yes.

Other than that there can be some psychological issues that make self-controlled treatment subjectively hard or impossible. But then we'd have found another condition that would need to be treated first, getting us back to where we started: Somebody running a study on the efficacy of a diet probably would want to preclude people psychologically unable to stick to it...