“Thyroid 4b” generally refers to thyroid nodules classified as category 4B under ultrasound. Thyroid nodules category 4B can be treated with surgery under the guidance of a doctor if necessary, and the benefit of having surgery is that it can treat the disease, and the disadvantage is that some side effects may be brought about by the surgery. 1. Surgery for category 4B thyroid nodules can treat thyroid nodules by removing malignant thyroid nodules or relieving some of the symptoms of compression caused by large thyroid nodules, such as difficulty in breathing and swallowing. 2. The disadvantage of surgery for thyroid 4B nodules is that levothyroxine is often required for treatment due to hypothyroidism brought about by the surgery. Hypoparathyroidism may also occur, usually due to injury to the parathyroid glands during surgery or damage to the recurrent laryngeal nerve. The decision to operate on a category 4B thyroid nodule should be made based on the size of the nodule, the benign or malignant nature of the nodule, and the individual’s tolerance for surgery. If a thyroid 4B nodule develops, it should be treated promptly in a hospital.