Body dysmorphic disorder often begins gradually. A person may notice that they are spending increasing time thinking about an aspect of their appearance, checking, comparing, seeking reassurance or avoiding situations where they feel their appearance will be scrutinised. These patterns can develop before a clinical threshold is reached and can affect daily life, relationships and work. A guide cannot diagnose BDD or determine whether appearance related distress is clinically significant. Appearance concerns can be connected with BDD, low self esteem, social anxiety, eating difficulties, trauma, depression, OCD or other difficulties. Physical symptoms, medication, neurodivergence and other factors can all affect a person's experience. New, severe or changing physical symptoms should be discussed with an appropriate medical professional before assuming a psychological explanation. Social media and image focused platforms can affect how people feel about their appearance. Research has explored associations between social media use and body image dissatisfaction. A guide cannot determine whether social media use is causing or maintaining appearance related distress for an individual, or what changes to social media habits would be helpful. Cosmetic procedures can be sought for many reasons. A guide cannot determine whether a person's interest in a cosmetic procedure is related to BDD or another explanation. Questions about a procedure, physical symptoms, complications or medical suitability should be discussed with the appropriate regulated health professional. CBT for BDD may be considered after individual assessment. Behavioural experiments, where they are clinically appropriate, are planned collaboratively with a suitably qualified clinician after discussion of the rationale, alternatives, safety and pacing. A guide is not a self directed programme. For related information, see BDD therapy at https://lyceumclinic.co.uk/therapy/body dysmorphic disorder/, the BDD clinical guide at https://lyceumclinic.co.uk/guides/body dysmorphic disorder cbt west london/, BDD and relationships at https://lyceumclinic.co.uk/guides/bdd and relationships west london/ and BDD at work and daily life at https://lyceumclinic.co.uk/guides/bdd work daily life/. If there is immediate danger, thoughts of self harm, an inability to stay safe or a sudden marked deterioration, call 999, attend A&E or use urgent local crisis or medical support.