Bigorexia nervosa (BN) is a controversial nosological entity, considered either a feeding/eating disorder (FED) or a subtype of body dysmorphic disorder (BDD). This rapid review aims to explore the characteristic features of BN and identify evidence-based therapeutic interventions for this condition. Three electronic databases (PubMed, Cochrane, and Google Scholar) were searched for relevant information about BN, and 26 reports were reviewed in detail. The results showed that bodybuilders, weightlifters, and other populations involved in athletic activities are the most vulnerable to the onset of this disorder. Patients with BN should also be screened for physical and psychiatric comorbidities and complications, such as anabolic steroid use disorder, physical exercise addiction, and depressive or anxiety disorders. The main differential diagnoses for BN are schizophrenia spectrum disorders, depressive disorders, anxiety disorders, bodily distress disorder, and obsessive–compulsive disorders. Using validated screening instruments is considered very important from a clinical perspective, with the aim of providing early identification of this disorder. Therapeutic interventions for patients with BN are still in the early phases of development, and no specific pharmacological treatment has yet been identified. Since it is similar to the obsessive–compulsive spectrum, cognitive behavioral therapy has been suggested as a useful intervention; however, it has not yet been validated in large-scale clinical trials. In conclusion, based on the reviewed data, clarifying the concept of BN is of practical importance for constructing adequate prevention strategies and validating proper therapeutic interventions.