Just as tuberculosis destroys his health lies and hypocrisy destroy family life The disease is hidden inside him just like corruption is hidden inside the Helmer marriage Rank s illness warns the audience that hidden sins always bring destruction Emotional Effect on the Play Dr Rank s illness also creates emotional impact He confesses to Nora that he will soon die He leaves his visiting cards with a black cross to announce his death This moment shocks Nora She loses her last friend and support His hereditary disease adds a tragic tone to the play and increases the sense of hopelessness Hereditary disease in A Doll s House is shown through Dr Rank s spinal illness It is inherited from his father It symbolizes social decay It adds tragic depth to the story Ibsen uses disease as a reminder that corruption like sickness passes through generations