Grey's Anatomy star Camilla Luddington has revealed her shock health diagnosis.

Speaking on her Call It What It Is podcast, the British-born actress, 41, said she had blood tests done and was diagnosed with "Hashimoto's hypothyroidism".

She said for a while she had been complaining about feeling "slothy" and "tired" and feels "relieved" she finally got a diagnosis for how she's been feeling.

Watch the video above.

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<div></img>'A little freaked out': Grey's Anatomy star Camilla Luddington shares health diagnosis</div>

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"As long as you've been listening to us, you've known that I joke about being slothy, just a little slower... slower, tired, want to be in bed, love a nap," she said.

"It never occurred to me that there could be a medical reason for that."

"My doctor was like, 'Everything looks great except this one little thing'. And I remember hearing the words 'autoimmune disease' and thinking, 'what the f--k?' and and then being told that I had something called Hashimoto's hypothyroidism and that it was very common."

Camilla Luddington at the 2022 People's Choice Awards on December 6, 2022.

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The star said she knew something was going on but thought she might me in "perimenopause'' or have a "deficiency".

"So truly, when they said autoimmune disease... I was a little freaked out. And then when they said it's really common, I was like, well that sucks, but okay. And then honestly I was relieved."

Hashimoto's disease affects the thyroid.

Luddington hails from the UK but is based in the US, believed to be in Los Angeles. 

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She plays Dr. Jo on Grey's Anatomy, and has appeared on the show for years.

She is married to American actor Matthew Alan, 47, who is known for 13 Reasons Why and Ghost Whisperer: The Other Side.

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