Actress and writer Carrie Fisher died of sleep apnea and other undetermined factors, the Los Angeles County Medical Examiner-Coroner said Friday.
The coroner's report also said Fisher, who died Dec. 27 at age 60, suffered from heart disease and other conditions related to drug use.
Sleep apnea is a common disorder in which one have one or more pauses in breathing or shallow breaths in one's sleep, according to the National Heart, Lung and Blood Institute.
Fisher, best known for her iconic role as Princess Leia in the "Star Wars" movies, suffered a medical emergency on a flight a week before she died.
Fisher starred in the wildly successful "Star Wars Epsiode IV: A New Hope," "The Empire Strikes Back," and "Return of the Jedi" alongside Harrison Ford and Mark Hamill. The trio returned to the big screen for last year's "Star Wars Episode VII: The Force Awakens," and she had a CGI-enhanced cameo in this month's "Rogue One: A Star Wars Story."
Fisher's mother, actress Debbie Reynolds, died a day after her daughter.
On Facebook she thanked "everyone who has embraced the gifts and talents of my beloved and amazing daughter.
"I am grateful for your thoughts and prayers that are now guiding her to her next stop."
Fisher's death prompted an outpouring of grief on social media, from co-stars Mark Hamill, Harrison Ford and Billy Dee Williams to other celebrities and legions of devoted fans.
Fisher spent most of her life in the spotlight. The daughter of Reynolds and singer Eddie Fisher, she made her acting debut at just 15 in the Broadway revival of the play "Irene."
Fisher was also an accomplished author, publishing her first novel, "Postcards from the Edge," in 1987. It was made made into a film starring Meryl Streep and Shirley MacLaine. She later published the autobiographical "Wishful Drinking" and the non-fiction follow-up "Shockaholic," among others.
Her memoir "The Princess Diarist," was published this year, and was based on diaries she kept while filming the original "Star Wars" trilogy in the late 70s and early 80s.
Her other film roles include "Shampoo," "The Blues Brothers" and "When Harry Met Sally...."
Fisher was married to musician Paul Simon from 1983 until the following year, although the pair had been dating since 1977 and dated again for a time after their divorce. During a break in the relationship in 1980, she was briefly engaged to Dan Aykroyd.
Simon's song "Hearts and Bones" is reportedly about their relationship.
She and talent agent Bryan Lourd later dated and had one child, "Scream Queens" actress Billie Lourd.
Fisher publicly disclosed her bipolar disorder diagnosis and her battles with addiction, and often incorporated her struggles and experiences into her literary and stage work.