Risks for any anesthesia are:

• Reactions to medicines
• Breathing problems

Risks for any surgery are:

• Bleeding
• Infection

Risks for thyroid removal are:

• Injury to the nerves in your vocal cord. You may have a weaker voice or a hard time swallowing thin liquids after surgery.
• Difficulty breathing. This is very rare. It almost always goes away several weeks or months after surgery.
• Bleeding and possible airway obstruction
• A sharp rise in thyroid hormone levels
• Injury to the nerves to your vocal cords and larynx. This injury can cause weakness or even paralysis on one side of your voice box and larynx. When this happens, you may have problems reaching high notes when you sing, hoarseness, coughing, swallowing problems, or problems speaking. These problems may be mild or severe.
• Injury to the parathyroid glands (small glands near the thyroid) or to their blood supply. This can cause low levels of calcium in your blood (hypocalcemia).