Can miraculous healings be equalized with "spontaneous remissions" from modern medical terminology? Following the trace of (mostly) medieval miracle accounts, the present paper, though arguing against the use of the term "spontaneous", supports the idea of equalization, finding clear examples of failed or incomplete healings, relapses, and the cases of saints who themselves were passing through the process of illness. In conclusion of this interdisciplinary approach combining historical material with modern knowledge, it is advocated that a significant corpus of miraculous healings have been based on suggestive mechanisms.