According to her representative, Loretta Swit won two Emmy Awards for his role in the popular comedy TV series M*a*s*H.
Her publicist Harlan Boll told the BBC that she died at her home in New York. Although the coroner's report is under trial, she may have died of natural causes.
On M*a*s*h, Swit plays Major Margaret, a U.S. Army nurse, Major "Hot Lips" Houlihan. The series was held during the Korean War a mobile army surgical hospital ran for 11 seasons from 1972 to 1983.
Swit has been nominated for numerous awards and has appeared in almost every episode of the series, including an ending that drew record-breaking American audiences.
The show remains one of the most successful and well-received series in American television history. Its season finale was the most watched episode of any TV series in history at the end of 1983.
As "Hot Lips," Swit plays a tough and fragile army nurse who has an affair with Larry Linville's Frank Burns.
The show uses comedy and mischief to address difficult issues such as racism, gender discrimination and the impact of PTSD in the military, as U.S. troops were withdrawing from Vietnam and dealing with the consequences of the conflict.
It is based on the 1968 book Marsh: Novels About Three Military Doctors, written by a former Army surgeon.
Swit was born in Loretta Szwed, New Jersey, and trained at the American Academy of Drama Arts in New York City.
Along with M*A*S*H, she has also participated in many other TV shows, movies and even game shows.
She has participated in Broadway dramas, including next year, and mom and Shirley Valentine – she won the Sarah Siddons Award for Top Chicago Theatre Award.
She wrote that her television work included appearances on the Muppet show Mission: Imposs: Impass and Murder.
In addition to her Emmy Awards, Sweet was nominated for four Golden Globe Awards.
"The performance is not hidden in me, it's revealed. The permission we bring to you," she said in an interview with Star magazine in 2010.
She spoke to the author's role on M*a*s*h: "Around the second or third year, I decided to play her as a real person in a clever way, even if it means hurting the joke. ... She is a constant range of character; she never stops developing."
Swit is also an artist and animal rights activist and has established a charity campaign to oppose animal abuse, according to a statement from public relations officer Boll.
Jamie Farr also starred in M*a*s*h as Klinger, calling his "adopted sister".
"From the first time I met her, I should have a one-day appearance on M*a*s*h, we hugged each other, which became a lifelong friendship," Fal said in a statement. "I can't start expressing how much she would miss."