Why does hoarseness sometimes occur after thyroid tumor surgery? Hoarseness can sometimes occur after thyroid lobe or subtotal thyroidectomy for thyroid tumor, which is related to the injury of the nerve that innervates the larynx (doctors call it the laryngeal nerve). Since this nerve is closely related to the thyroid gland during its journey into the larynx and its position is not very constant, it can often be injured during thyroid surgery. If the laryngeal nerve is severed on one side, hoarseness may occur; if both sides are severed, loss of voice and asphyxia may result. The occurrence of this complication is sometimes unavoidable, in addition to the skill level of the surgeon, such as anatomical variation (not following the conventional anatomical itinerary) or tumor involvement of the nerve. Hoarseness occurs immediately after surgery, mostly due to direct severance, excessive stretching or clamping of the nerve. If hoarseness occurs late after surgery, it is mostly due to edema in the operated area. As long as the nerve is not cut, it can be recovered in 3-6 months after surgery, and neurotrophic drugs such as vitamin B1 and B12 can be used under the guidance of the doctor. If the nerve is cut directly during surgery, the cut nerve can be anastomosed in time and the success rate is also very high. However, if it is not detected in time during surgery and only after surgery, there is no effective treatment. In addition, the other nerve that innervates the laryngeal muscle movement is the extralaryngeal branch of the superior laryngeal nerve. Once it is damaged, it can cause low tone and choking (mainly when eating a liquid diet). Why does hand numbness occur after thyroid tumor surgery? After total thyroidectomy, patients with thyroid cancer may experience numbness in the hands and feet and flexion of the fingers of both hands, which doctors call “midwife’s hand”. This is due to the hypoparathyroidism caused by the surgery. There are generally two pairs of parathyroid glands, which look like green beans or smaller, and are located on the lateral and posterior sides of the upper and lower poles of the thyroid gland. They are endocrine organs that secrete parathyroid hormone and play an important role in regulating the body’s calcium and phosphorus metabolism. If it is removed together with the thyroid gland, a decrease in blood calcium may occur, resulting in increased excitability of the vascular muscles of the body and twitching of the hands and feet, or in severe cases, generalized convulsions and respiratory distress. Sometimes, even though the parathyroid glands are not completely removed, the residual parathyroid glands may be ischemic and may also cause parathyroid insufficiency. To prevent this, one or two parathyroid glands should be preserved as much as possible during surgery. If the above symptoms occur after surgery, oral calcium preparations or intravenous calcium infusion can be used in severe cases.