Kate Beckinsale opens up about health condition after facing cruel body shaming

Kate Beckinsale has shed more light on living with a rare autoimmune disease following years of public discussion about her body weight.

The actress, 53, took to social media to share a 13-part video in which she discussed her diagnosis of mast cell disease and mast cell activation syndrome, her symptoms and how she hopes opening up about her experience can help others,

She started the multi-part post saying: ‘As I’m sure you’re aware, anytime I post a photo of myself, I receive an enormous amount of comments telling me how disgusting I look and I’m anorexic or I’m on meth or that I’ve lost so much weight.’

The screen star continued: ‘First off, I’ve lost my entire family, except my precious daughter, in a short amount of time.’ Beckinsale’s mother, Judy Loe, died in July 2025 after a cancer diagnosis, just 18 months after she lost her stepfather Roy Battersby in January 2024.

‘The second thing is, I have a condition, which is an autoimmune condition called mast cell activation syndrome, and there’s another one called mast cell disease, and there’s mastocytosis.

‘This is something that I was diagnosed with 16 years ago, and I was really, really lucky that I had an amazing GP in London who called it and sent me to, at that point, the one guy in the world in New Jersey who was the expert in that,’ she explained.

Talking about how underdiagnosed this condition is, she shared that in her case her ‘stomach is ground zero’ for how this disease presents itself.

Later in her video, she stated that in 2026, when we’ve lost people like Caroline Flack and Chadwick Boseman and watched figures like Perez Hilton post distressing online content or stars like Ariana Grande withdraw from the spotlight, it’s important to remember we ‘don’t know what’s going on in people’s lives.’

She noted: ‘Treat people just how you’d like to be treated yourself, give people a little grace. If you don’t have anything nice to say, maybe don’t say anything.

Calling it ‘not necessary for everyone to know your opinion on what somebody else’s body looks like’, she urged people to not add to the troubles people are already dealing with, unbeknownst to strangers online.

‘You don’t want to be the last straw for somebody, you don’t want to be the thing that makes them more sick, just keep going, it’s not hard.’

In the caption, she further encouraged people to seek healthcare advice if they have any relevant symptoms.

Meanwhile, in the comments, which were flooded with support, she further opened up about what led to her current health issues.

‘For me it was a horrific marriage combined with glandular fever, and that’s what tipped it. I had not had a single allergy as a child, even though I’ve had a lot of trauma as a child, but I was pretty much tied up for it, and that sent me over the edge,’ she told one commenter.

This is not the first time Beckinsale has opened up about how mast cell disease is impacting her life.

In May 2024, she shared a lengthy response to the slew of comments concerned about her weight, pointing out she had had a ‘severe flare-up’ of mast cell activation syndrome.

‘That’s what I am prepared to disclose that has contributed to some weight loss.

‘What you think of my appearance and how I should look, independently of any circumstances in my life and my family is not important.

‘I am trying to survive what feel like unbearable losses, reactivated PTSD from discovering my very young father’s almost dead body as a very young child alone in the night, and working to support the family I have left,’ she said at the time.

Beckinsale is not the only celebrity to speak about having mast cell activation syndrome in recent months. Game of Thrones star Emilia Clarke also emotionally opened up about how the autoimmune disease has shaped her life.