Grey's Anatomy actress Camilla Luddington has been diagnosed with Hashimoto's disease. The 41-year-old actress, who has played Dr. Jo Wilson on the medical drama since 2012, revealed that she had been "feeling slothy" for some time before having her bloodwork done around two and a half months ago. The doctor eventually told her she has a condition called Hashimoto's hyperthyroidism, which affects the thyroid gland. "I remember hearing the words 'autoimmune disease' and thinking, 'What the f**k?'" Luddington told her co-star Jessica Capshaw on their Call It What It Is podcast. "Truly, when they said 'autoimmune disease,' I was really freaked out, and then when they said it's really common, I was like, 'That sucks but OK.'" Hashimoto's disease is an autoimmune disorder in which the immune system attacks the thyroid gland, meaning it cannot produce enough thyroid hormone. Symptoms include fatigue, increased sensitivity to the cold, and a puffy face, among others. Luddington told Capshaw that she "knew something was up" because she was "really f**king tired all the time" and wondered if she had entered perimenopause. "It makes you feel tired and cold. It can make you foggy, depressed, you can have dry skin, your hair can thin. Basically, you're feeling gorgeous with Hashimoto's," the actress added sarcastically. "It got to the point where, by 11 a.m., it felt like I had chugged some Benadryl and I needed to nap, and it didn't matter how much sleep I'd gotten the night before. There was no pushing through the day." Luddington noted that she is doing much better since being prescribed a medication to treat thyroid hormone deficiency. "I'm still not normal, (but) I do feel a lot better," she added. "My energy's a lot better. I'm not as puffy anymore."