Thyroid

Postoperative problems affecting the thyroid (gland in the neck) include

Residual function of the gland being too high or too low.
Scar. Usually very aesthetic, lying in a skin crease across the neck. Special staples are often used in case they need to be removed quickly.
Bleeding. The thyroid gland is very vascular and bleeding after the operation can compress the underlying windpipe. This is why easy to remove staples are popular.
Accidental damage or removal of the underlying parathyroid glands (four tiny glands located near the thyroid gland; parathyroid glands produce a hormone (PTH) which controls Ca²⁺ and phosphate levels in blood; important for functioning of nerves, muscles and bones), leading to disturbances in calcium ion and phosphate levels in the blood.
Damage to the recurrent laryngeal nerve, leaving a hoarse voice.
Minor difficulties in swallowing.