Authorities now know what led to Betty White's death ahead of her 100th birthday.

The actress, known for her roles in "The Golden Girls," "The Proposal" and other popular shows and movies, passed away at age 99 at her home in Los Angeles, California, on Dec. 31.

According to her death certificate obtained by E! News, White died of a cerebrovascular accident, or a stroke. She suffered the stroke six days before she died.

The medical incident happens when part of the brain experiences a loss of blood flow, according to the National Library of Medicine, which says it can cause "lasting brain damage, long-term disability, or even death."

A few weeks before her death, White told People magazine that she was "so lucky to be in such good health and feel so good at this age."

White's friend and agent, Jeff Witjas, previously told E! News that she "died peacefully in her sleep at her home" and debunked rumors that her death was associated with the COVID-19 vaccine.

"People are saying her death was related to getting a booster shot three days earlier but that is not true. She died of natural causes," Witjas said in a statement to E! News on Jan. 3. "Her death should not be politicized — that is not the life she lived."

He went on to pay tribute to the "great lady" she was, remembering her for her legacy as an animal lover and activist.