‘Grey’s Anatomy’ star diagnosed with Hashimoto’s: What to know about the disease

“Grey’s Anatomy” star Camilla Luddington recently revealed she has been diagnosed with Hashimoto’s disease, an autoimmune disorder.

The British actress, known for her role as Dr. Jo Wilson, first shared the news of her diagnosis on the “Call It What It Is” podcast, which she co-hosts with fellow “Grey’s Anatomy” star Jessica Capshaw.

Luddington, 41, spoke more about her diagnosis in an interview with ABC News chief medical correspondent Dr. Tara Narula, explaining that she decided on her own to get bloodwork done after feeling unusually tired.

“When I was having my blood drawn, the doctor said to me, ‘Is there any reason for concern?,’” Luddington told Narula in the interview that aired Friday on “Good Morning America.” “And I said, ‘I’m so tired, I must be in perimenopause or I’m deficient in something, and so I want to get my hormones checked.’”

Phillip Faraone/Getty Images for MPTF NextGen – Camilla Luddington attends the MPTF NextGen Annual Summer Party fundraiser on June 22, 2025 in Los Angeles, California.

When she received the diagnosis of Hashimoto’s disease, Luddington said she actually felt relieved.

“I think when I realized how common it was, it became less scary. And then, honestly, one of the first things I felt was relief,” said the actress, who has been part of the “Grey’s Anatomy” cast since 2012. “I was having a really hard time functioning as a parent and this gave me reason to believe I can get better. I can take medication. This is something that I can manage.”

Hashimoto’s disease, an autoimmune disease where the body attacks its own thyroid, affects roughly 1% to 2% of the population in the United States. The disease is four to 10 times more common in women than in men, according to the National Institutes of Health’s National institute of Diabetes and Digestive and Kidney Diseases.

Luddington told Narula that she is now taking medication for her condition and is already seeing improvements in her health.

She said she plans to continue to document her journey with Hashimoto’s disease on her podcast in order to help raise awareness of the disease.

“I imagine there are so many people like me on this journey that are also really confused, and so I wanted to bring people along,” Luddington said. “I want to be able to talk to experts and doctors, get information and get more information out there. And I also just think that when you share a story or a diagnosis, it makes other people feel like they’re not alone.”

What to know about Hashimoto’s disease

Hashimoto’s disease is an autoimmune disorder that can cause hypothyroidism (underactive thyroid) or, in rare cases, hyperthyroidism (overactive thyroid), according to the NIDDK.

The thyroid, a small, butterfly-shaped gland in the neck, becomes damaged in people with Hashimoto’s, NIDDK states on its website.

The immune system produces antibodies that attack the thyroid, leading to the accumulation of white blood cells which destroy thyroid’s cells that produce hormones.

This condition is also known as Hashimoto’s thyroiditis, chronic lymphocytic thyroiditis, or autoimmune thyroiditis, according to NIDDK. While the exact number of people affected in the U.S. is unknown, Hashimoto’s is the leading cause of hypothyroidism, which impacts about 5% of Americans.

NIDDK notes that early on, Hashimoto’s may not show symptoms, but as it progresses, it can cause fatigue, weight gain, cold intolerance, joint pain, constipation, dry skin, irregular periods and a slowed heart rate. It often leads to hypothyroidism, but in its early stages, it can cause symptoms of hyperthyroidism.

The thyroid may also enlarge, creating a swollen neck or goiter, which can shrink over time.

‘Grey’s Anatomy’ star opens up about battle with postpartum anxiety, severe PMS disorder

According to NIDDK, the exact cause of Hashimoto’s is unknown, but it is often linked to a family history of thyroid disease.

Several factors, including genes, viruses like hepatitis C, certain medications, and exposure to toxins such as nuclear radiation, can contribute to its development.