The time it takes for Hashimoto’s thyroiditis to develop into hypothyroidism varies from person to person, and may be around 2-3 years or 10-20 years, with some patients not becoming hypothyroid for life. If you have Hashimoto’s thyroiditis, your body has too many thyroid peroxidase antibodies and thyroglobulin antibodies, which destroys your immunity and leads to insufficient secretion of thyroid hormones, and you may eventually become hypothyroid. The development of Hashimoto’s thyroiditis into hypothyroidism may take about 2-3 years or 10-20 years. If a person with Hashimoto’s thyroiditis has normal thyroid function, he or she may not become hypothyroid for life. Therefore, the exact time it takes for Hashimoto’s thyroiditis to become hypothyroid tends to vary from person to person, and there is no exact time limit. If you have Hashimoto’s thyroiditis, it is recommended that you cooperate with your doctor for treatment as soon as possible to avoid the condition from worsening and developing into hypothyroidism.