Recently, Arjun Kapoor opened up about being diagnosed with an autoimmune condition called Hashimoto's disease at 30. He also revealed that he was dealing with other health setbacks which are associated with the condition back-to-back in 2014-15. "You will have moments of self-doubt in any profession. You fight through it. You look for validation. I am a fat kid at heart. I was diagnosed with mild depression, which was circumstantial. When you have an autoimmune disorder — I have something called Hashimoto’s — it’s an extension of having a thyroid issue, but your antibodies fight against you. So, it’s almost like I can take a flight and gain weight because the body goes into stress," he said in an interview. What Is Hashimoto's Disease?It is an autoimmune disease that occurs when the body's immune system attacks the thyroid glands and reduces its ability to produce hormones. This can lead to underactive thyroid, also known as hypothyroidism. Anyone diagnosed with the disease will experience an enlarged thyroid, fatigue, weight gain, hair changes, slow heart rate, joint or muscle pain, constipation, menstrual irregularities, depression, or memory problems. It is named after Dr Hakaru Hashimoto, a Japanese doctor and medical scientist who first described this disease in 1912 as a new type of lymphomatous thyroid tumour in Japan. It was many years later that it was recognised as an autoimmune disease. A Disease That Can Be Passed DownWhile this is most common in middle-aged women, it can occur to anyone at any age. People are more likely to develop it if they have a family history of thyroid disease. Right so, Kapoor shares that his late mother and his sister also had the same condition. "That happened to me when I was 30, and I defied it. I said, no, it can’t be because my mom used to have it. I used to be nonchalant because I became fit; I lost 50 kgs. I said, it is not going to bother me. My sister also has it. I said I will deal with it. But I remember when I was doing Tevar, Ki and Ka, Half Girlfriend, and Mubarakan, it started showing up. I shot back-to-back. If I look back, I was trying but my body kept changing. That’s 2014-15, and that’s 7-8 years of holding that physical trauma," he shared.Why Does Autoimmune Diseases Happen?As per John Hopkins Medicine, autoimmune disease occurs because the body's natural defenses, the immune system, starts to attack body's healthy tissues. Researcher have found that when the body senses danger from a virus or infection, the immune system kicks into gear and attacks it. Experts also say that this is the third most common condition after obesity and diabetes that affects people across ages. Kapoor also shares that this condition forces his body to go into "stress mode", which also affects his weight, and energy levels. What Can Be Done?While there are hormonal replacement therapy, a Hashimoto's Diet is said to have worked for many people:Gluten-free or grain-free dietSugar-free diet: sugar can increase inflammation and provoke autoimmune thyroid flares. It can also throw blood sugar our of balance, thus a sugar-free diet helps those with the condition.Paleo diet: It mimics the eating patterns of our ancestor and emphasises on the concept of unprocessed food. The Autoimmune Paleo Diet (AIP) is thus an attempt to avoid food that can cause inflammation and damage to the gut. Dairy-free dietLow Glycemic Index Diet: It measures how each food affects your blood sugar levels as sugar imbalances are common in people with Hashimoto's.