Hi, Parathyroid surgery can result in complications, but the rate of complications are lesser in experience hands of surgeons who have done many of such surgeries previously and also the rate of complications are lesser with adoption of the latest minimally invasive technologies. Make sure you ask the surgeon about his experience of performing such surgeries. The complication on voice is hoarseness of voice rather than loss of voice. Sometimes hoarseness can be transient due to stretching of nerve during operation and sometimes it could be more permanent due to injury to the nerve. A carefully done surgery in experienced hands can avoid this; sometimes in cases of tumor the nerve has to be sacrificed if required. It is better to discuss face to face with your surgeon itself. Regards, Sreenivasan