Background: Psychological stress is a reaction to an unexpected situation that favours adaptation and response to the event. However, when psychological stress is chronic or very intense, it can induce changes in various systems and tissues, causing diseases or aggravating existing ones. Objective: To briefly analyse the pathophysiological conditions caused by psychological stress. Method: A narrative review of the scientific literature on pathophysiological conditions as a consequence of psychological stress was performed. Results: Psychological stress can induce various conditions at the gastrointestinal, immune and cardiovascular levels. This is mainly due to the neurobiological and endocrine response because when faced with a stressful stimulus, a deregulated release of glucocorticoids and catecholamines is generated, altering the normal physiology ...