To obtain hemorrhage rate after coblation tonsillectomy, and to investigate risk factors of hemorrhage after coblation tonsillectomy in children.

This study is a prospective and multi-centre trail in China. It intends to enroll 25000 patients underwent coblation tonsillectomy in 22 clinical centers in China. Hemorrhage rate and risk factors of hemorrhage after coblation tonsillectomy will be investigated through questionnaires.

Inclusion Criteria:

1. under 18 years old;
2. Clear indications for tonsill surgery;
3. No clear contraindications for tonsill surgery;
4. Parents of the children patients accept surgical treatment;
5. Parents of the children patients able to cooperate with the visit and follow-up.

Exclusion Criteria:

1. Children patients with a history of adenoid or tonsillectomy surgery;
2. Associated with refractory bleeding diseases;
3. Combined with cleft palate;
4. Down syndrome, Prader-Willi syndrome (PWS) or other chromosomal abnormalities;
5. Neuromuscular diseases (including cerebral palsy);
6. Other diseases that affect physical health, such as severe heart disease, kidney disease, lung disease, etc;
7. Contraindications to surgery and anesthesia;
8. Unable to obtain informed consent.

Enrolled patiens are children who underwent coblation tonsillectomy from multi-centers in different provinces of China.