The risks that an adult might face during a tonsillectomy are, headache,Vomiting,Nausea, sore muscles due to the anesthetic that is used to put the patient to sleep during the surgery.
Bleeding during surgery and bleeding during the healing of the tonsils after surgery can happen and even infections can happen after a tonsillectomy.
The mortality rate of tonsillectomies are between 2 to 4% which is 1 in 15,000 people due to the bleeding complications with the anesthetic or airway obstructions.
Most times a person won't have any complications with the tonsillectomy but it does happen.