If your mobile, you can go to the Hua Hin Hospital 3 located on Soi Hua Hin 89 going south out of town on Phetchkasem Road (Hwy 4).The Soi is directly on the right of the GDL POOL SHOP. Entrance of the Soi has large sign with Green Cross. About 200m down on the right is the hospital.They have a dedicated massage unit (you may need to make an appointment). My wife has used this often. Being Thai she pays around ThB 200 p.h but I don't know the price for non-Thai.