Inclusion Criteria:  Gestational age > 37 wk Delivery of singleton, healthy newborn baby Within 7 days postpartum Within 24 hours from initial painful breast engorgement Difficulty on lactation due to plugged ducts, SI index ≧ 5 (0-19)  Exclusion Criteria:  Fever>37.5∘C Mastitis or breast abscess Signs of sepsis or other infection Perinatal mother and infant diseases (Gestational hypertension、Gestational Diabetes Mellitus、Pre-eclampsia 、Gestational thyroid diseases or Intrauterine growth retardation) Psychological diseases Bleeding tendency Artificial valves Pacemaker Epilepsy Consciousness disturbance Skin infections Hepatitis B carrier Acquired Immune Deficiency Syndrome Breast tumors Breast Surgeries