Can seaweed and kelp "enlarge" thyroid nodules?

Whether seaweed and kelp enlarge thyroid nodules depends on whether thyroid function is normal: those with normal function can eat one or two bowls of seaweed soup or sushi in moderation without issue, while those with hyperthyroidism must strictly follow a low-iodine diet, avoiding seaweed, kelp, kombu, and deep-sea fish and shrimp. Those with nodules should have regular ultrasound follow-up; if a nodule grows rapidly within a short period, or if hoarseness, difficulty swallowing, or breathing difficulties occur, seek medical attention promptly to assess whether a fine-needle aspiration cytology (FNAC) is needed.