<P> Cristina Yang, M.D., Ph. D., is a fictional character from the medical drama television series Grey's Anatomy, which has aired for over 14 years on the American Broadcasting Company (ABC) in the United States . The character was created by series producer Shonda Rhimes, and is portrayed by actress Sandra Oh . Introduced as a surgical intern at the fictional Seattle Grace Hospital, Yang worked her way up to resident level, eventually becoming a cardiothoracic surgical fellow, while her relationships with colleagues Meredith Grey (Ellen Pompeo), George O'Malley (T.R. Knight), Izzie Stevens (Katherine Heigl), and Alex Karev (Justin Chambers) formed a focal point of the series . Yang earlier in the series got engaged to Preston Burke (Isaiah Washington), in the past had a relationship with renowned surgeon and mentor Colin Marlow, and wed but later divorced Owen Hunt (Kevin McKidd). </P> <P> Oh originally auditioned for the role of Miranda Bailey, although Chandra Wilson was ultimately cast in the part . Oh has received generally positive reviews for her portrayal, with Mark Perigard of the Boston Herald considering her friendship with Meredith to be "the secret core of Grey's". Oh has also garnered numerous awards and nominations for her role as Yang, including Golden Globe and Screen Actors Guild Award wins in 2006 . She was additionally nominated for the Primetime Emmy Award for Outstanding Supporting Actress in a Drama Series each year, from 2005 to 2009 . Characterizing the character, ABC noted her competitiveness, ambition, and intelligence as her main traits, while her aggressive, and tactless attitude was highlighted as her main weakness . In May 2012, E! Online reported that Oh had signed on for two more years, along with her fellow cast members . Oh left the show after season 10, and her character Cristina Yang was written out of the storyline as a main cast member . </P> <P> Cristina Yang is introduced as a graduate from Smith College and a fellow surgical intern to Meredith Grey (Ellen Pompeo), Izzie Stevens (Katherine Heigl), George O'Malley (T.R. Knight), and Alex Karev (Justin Chambers); the five of them working under Miranda Bailey (Chandra Wilson). An atheistic competitive intern of Korean - American ancestry, she first desired to become a doctor after a childhood car accident which killed her biological father . Yang also suffers from dyslexia, and was raised in Beverly Hills, California by her mother and supportive Jewish stepfather . She has BA from Smith College, an MD from Stanford University and a PhD from University of California, Berkeley, making her a "double doctor". While her emotional pragmatism, competitive perfectionism, and logical nature lead many to view her as a cutthroat "robot", Cristina hits it off with Meredith on their first day and the pair soon become best friends and each other's "person", sharing the same "dark and twisty" sense of humor . </P> <P> During her internship, Cristina has an on - off relationship with the chief of cardiothoracic surgery Preston Burke (Isaiah Washington) that leads to an accidental pregnancy . Yang schedules an abortion without telling him about the pregnancy due to Burke's behavior towards their lack of relationship status . However, Yang experiences an ectopic pregnancy and Burke discovers the pregnancy after Yang collapses from a burst fallopian tube . Burke and Yang begin a relationship in the aftermath of her miscarriage . After Burke is shot in the arm and develops a hand tremor, Yang helps him cover it up by developing a covert partnership wherein she performs most of his surgeries . Yang initially denies involvement during a confrontation, but then confesses everything to Richard Webber (James Pickens, Jr .), the chief of surgery . Yang's actions jeopardize Burke's chances of becoming chief, which he sees as a huge betrayal . After a short breakup, Yang breaks the silence and Burke proposes marriage, which Yang accepts after eight days of hesitation . Burke calls off the wedding, leaving Yang at the altar . She goes on her honeymoon to Hawaii with Meredith to recover, returning to discover that Burke has disappeared from her life and transferred to a different hospital . </P>

When does cristina go back to being a surgeon