Intolerance to wheat and gluten intake has gained public and scientific interest in recent years. Celiac disease (CD) and wheat allergy are wheat-related disorders with a well-defined etiological mechanism alongside corresponding diagnostic tests. In addition, patients also self-report intolerance toward wheat and gluten that does not meet the criteria of CD and wheat allergy. This gives rise to a third category, namely non-celiac wheat sensitivity (also referred to as non-celiac gluten sensitivity). However, this category is controversial. Unlike CD and wheat allergy, the pathophysiological mechanism is unknown. When conducting double-blinded placebo-controlled trials, only a small proportion of patients can correctly identify gluten from a placebo based on symptoms, indicating a substantial nocebo component. In fact, it has been posited that non-celiac wheat sensitivity is simply a form of irritable bowel syndrome. The aim of this review is to provide an overview of the epidemiology, etiology, clinical manifestations, diagnosis, and management of the 3 abovementioned conditions.