Scientists don’t know yet what makes the immune system attack healthy thyroid cells1. Nevertheless, there are factors that can facilitate the development of Hashimoto’s thyroiditis. 

  • Biological sex. Thyroid problems are approximately 7 times more frequent in females2.
  • Age. Most often, autoimmune thyroiditis is diagnosed in people from 30 to 50 years old, although there have been cases of earlier disease development. 
  • Pregnancy. If a woman has had postpartum thyroiditis, her risk of AIT is elevated. This risk is increased further in the event of a new pregnancy. This can be explained by the ability of the immune system to “remember” hormonal level fluctuations during pregnancy. This can become a trigger for the development of AIT. 

~ 20% of women who have thyroid problems during the first year after having a baby, develop Hashimoto’s later.2

  • Genetics. This disease has a hereditary component, although no specific gene responsible for Hashimoto’s thyroiditis has been identified. 
  • Other autoimmune disease. One can be at higher risk for Hashimoto’s thyroiditis if they have another autoimmune disease.
  • Radiation. The risk of autoimmune thyroiditis is higher in people who have been exposed to excessive levels of radiation at any time in their lives.

Hashimoto’s thyroiditis is more probable in people with other autoimmune diseases, including autoimmune hepatic disorders, celiac disease, rheumatoid arthritis, type I diabetes mellitus, lupus, and Addison disease (adrenal disorder). 

According to the American Thyroid Association, about 12% of the US population are at risk of developing thyroid disease. At the same time, 60% of people with thyroid issues do not even suspect them, because the first symptoms of Hashimoto’s thyroiditis can manifest months after the disorder has started. Risks of having undiagnosed thyroid disease include cardiovascular disorders, difficulty getting pregnant, and complications during pregnancy. 

The first signs of Hashimoto’s thyroiditis can be easily confused with symptoms of another disease or just general stress.3 Here are some of them: 

  • Tiredness even after a long rest
  • Menstrual cycle disorders
  • Constant stress or depressed mood
  • Sleepiness and apathy
  • Hair loss and fragile nails
  • Abrupt body mass gain or loss

To make sure you get diagnosed in a timely manner and are able to start treatment at an earlier stage, make a habit of having regular medical checkups, especially if you’re in a risk group.

Key takeaways

  1. Hashimoto’s thyroiditis risk factors include biological sex, age, and pregnancy (especially second and later pregnancies), as well as genetics, other autoimmune condition, and exposure to radiation. Nevertheless, researchers still haven’t discovered what causes the immune system to attack healthy cells in the thyroid gland. 
  2. Hashimoto’s thyroiditis symptoms can be easily confused with manifestations of other conditions, which increases the risk of later diagnosis and longer treatment. Do not wait too long to go to the doctor, even if you think your wellbeing issues are unrelated to your thyroid. 
  3. Do not forget about regular checkups, as early stages of Hashimoto’s are often asymptomatic.