If the thyroid nodules are caused by autoimmune thyroiditis such as Hashimoto’s thyroiditis, kelp can usually be eaten in moderation. If the thyroid nodules are caused by hyperthyroidism, kelp is usually not recommended. 1. Hashimoto’s thyroiditis: Hashimoto’s thyroiditis stimulates the thyroid follicles, leading to localized hyperplasia and fibrosis, which results in thyroid nodules. Hashimoto’s thyroiditis is one of the most common causes of hypothyroidism, which requires thyroid hormone therapy, and kelp is rich in iodine, which has a role in promoting thyroid hormone synthesis. Therefore, the thyroid nodules caused by Hashimoto’s thyroiditis can eat kelp appropriately. 2. Hyperthyroidism: the disease itself is caused by excessive secretion of thyroid hormones, and kelp is rich in iodine will promote the synthesis of thyroid hormones, so patients with hyperthyroidism are not recommended to eat kelp. Whether patients with thyroid nodules can eat kelp, it is recommended to consult a specialized doctor.