LOS ANGELES — For actor Camilla Luddington, a recent blood test held the key to understanding her "slower" and lower-energy demeanor.

The "Grey's Anatomy" star on Wednesday opened up about her health, revealing she has been diagnosed with an autoimmune disorder known as Hashimoto's disease. In an episode of her and co-star Jessica Capshaw's "Call It What It Is" podcast, Luddington said she often feels "slower, tired, [wants] to be in bed" and that "it never occurred to me that there could be a medical reason for that."

Luddington, 41, told her co-host she had blood work a couple of months ago and her doctor flagged "one little thing." Though she was "a little freaked out" to hear the words "autoimmune disease" from her doctor, Luddington said they reassured her that Hashimoto's hyperthyroidism is a "very common" disorder.

Hashimoto's disease affects the thyroid gland, which is responsible for producing hormones and regulating many bodily functions, according to the Mayo Clinic. The slow-progressing disease can bring about a range of symptoms including fatigue and sluggishness, increased sensitivity to cold, dry skin, hair loss and weight gain.

Luddington said she experienced a handful of the symptoms associated with Hashimoto's, but dismissed them as signs of aging and perimenopause. Relieved to learn the cause of her symptoms, Luddington offered her own understanding of the disorder: "Makes you a little slothy."

"I didn't realize how exhausted my body was," said Luddington, who stars as Dr. Jo Wilson on "Grey's."

Since receiving her diagnosis, Luddington said she has been taking medication to manage her disorder and has also returned to exercising. During the podcast episode, she and Capshaw also talked about the pitfalls of medical advice from TikTok "doctors," and encouraged listeners to share their experiences with autoimmune disorders.

Luddington joins several other stars, including "The Boys" star Erin Moriarty and "Star Wars" actor Daisy Ridley, who have been open about their autoimmune disorders in recent years.

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