Although there has been a lot of research looking at the placebo response, nocebo responses in the healthcare setting have been largely overlooked. This article explores the potential role of negative patient–doctor communication in facilitating nocebo responses in the medical consultation. We suggest that invalidation, that is, communicating a lack of understanding and acceptance to the patient (albeit unintentionally), is a key factor in understanding the nocebo response. This article reviews evidence from the experimental and healthcare setting, which suggests that the negative effects of invalidation may be stronger than we think.