Inclusion Criteria:  Age of 16 years and older. Both sexes. Patients who are candidate for thyroid surgery and euthyroid.  Exclusion Criteria:  - Patients with hyper- or hypo-thyroid status. Patients who were unfit for surgery. Patients with unilateral or bilateral vocal cord palsy on preoperative indirect laryngoscopy Patients with thyroid malignancy by preoperative FNAC. Patients with hypersensitivity to methylene blue were excluded.