An epiphenomenon (plural - epiphenomena)'s a secondary phenomenon that occurs alongside or in parallel to a primary phenomenon. Examples of epiphenomena Epiphenomena in medicine In medicine, an epiphenomenon's a secondary symptom seemingly unrelated to the original disease or disorder. For example, having an increased risk of breast cancer as a result of taking an antibiotic's an epiphenomenon. It isn't the antibiotic that's causing the increased risk, but the increased inflammation associat… (More on Epiphenomenon)