After obtaining written informed consent, patients of clinically diagnosed with CTS were randomized into intervention and control group. Participants in intervention group received one-dose ultrasound-guided PRP injection and control group received one-dose ultrasound-guided 5% dextrose injection. No additional treatment after injection through the study period. The primary outcome is visual analog scale (VAS) and secondary outcomes include Boston Carpal Tunnel Syndrome Questionnaire (BCTQ), cross-sectional area (CSA) of the median nerve, sensory nerve conduction velocity of the median nerve, and finger pinch strength. The evaluation was performed pretreatment as well as on the 2nd, 4th, 8th, 12th, 16th and 24th week after the treatment.