ObjectiveTo explore the risk factors and bleeding points associated with postoperative hemorrhage after thyroidectomy and provide clinical basis for prevention of postoperative bleeding.MethodsThe clinical data of 21 patients with postoperative hemorrhage and 63 patients without postoperative hemorrhage who underwent thyroidectomy from Nov. 2010 to Nov. 2017 in West China Hospital were retrospectively analyzed.ResultsUnivariate analysis showed that hypertension, maximum tumour dimension, lymph node metastasis, recurrent laryngeal nerval infiltration, T stage, N stage, serum triglyceride, and serum high density lipoprotein were significantly associated with postoperative hemorrhage (P<0.05). Multivariate analysis showed that lymph node metastasis (OR=16.219, P=0.002) and low serum high density lipoprotein (OR=0.035, P=0.006) were risk factors for postoperative hemorrhage. Among the patients with postoperative bleeding, the most common five bleeding sites were: ribbon muscle and sternocleidomastoid muscle (both was 19.2%), esophageal tracheal surface blood vessels (11.5%), thyroid bed (7.7%), and larynx recurrent paravascular small vessels (7.7%).ConclusionsLymph node metastasis and serum HDL are independent risk factors of hemorrhage after thyroidectomy. The predilection site for postoperative bleeding is mainly the neck muscle.