Choo grew up in Cleveland, Ohio. Her parents emigrated from Korea in the 1960s. She graduated in 1994 with a degree in English from Yale College. She was an intern at The Plain Dealer, a newspaper in Cleveland. She earned a medical degree at Yale University in 2001. She was a resident at Boston Medical Center. In 2009, she returned for further training, earning a Master's in Public Health at Oregon Health & Science University.
