Selma Blair revealed that she was told to "make plans" for her death in an incredibly emotional documentary trailer.

The forty-nine-year-old reportedly believed she was "shooting the final days of (her) life" while filming her documentary, Introducing, Selma Blair. The film follows the actress' journey as she battles multiple sclerosis (MS), a condition that can affect the brain and spinal cord, causing a wide range of other symptoms including vision loss and nerve deterioration. The actress, best known for her roles in Cruel Intentions, Legally Blonde, and Hellboy, was diagnosed with the condition in 2018.

The trailer, which was released on Thursday, delves into Blair's exploration of her journey and how resilience plays a crucial part in defeating it. Speaking on the voiceover, she says this: "I always thought I was on a reality show.

"Like I was in a documentary, but only God would see it and disapprove."

Blair also explains how it felt to be told to prepare for her death, with the occasional throw-in of a joke here and there.

"I was told to make plans for dying," Blair said in the 2-minute clip. "Not because I have MS, because I'm fighting MS."

She spoke out about her diagnosis on Instagram, telling her followers that she might have actually had the condition for a while now, but didn't realize.

"I have Multiple Sclerosis. I am in an exacerbation," she wrote in an Instagram post in 2018.

She continued: "I am disabled. I fall sometimes. I drop things. My memory is foggy. And my left side is asking for directions from a broken GPS. But we are doing it."

The heartbreaking footage even shows Blair while she's suffering a medical emergency. The clip is hard to watch and some viewers might find it distressing.

"I had a complication," she says of the incident. "Suddenly it was like the most horrible pain in my heart. And I can't say 'I can't breathe' because I couldn't breathe."

But Blair does not stop fighting and her resilience is extremely commendable. She continues to live her life to the fullest even despite her condition as proved by her social media posts.

Introducing, Selma Blair will hit theaters on October 15th before it becomes available on the Discovery+ streaming service on October 21st.