Dr. Loan B. Hsieh, Pediatric Hematology

An expert in pediatric hematology-oncology, Dr. Loan Hsieh specializes in all aspects of hematology with an emphasis in Factor 13 deficiency and rare bleeding disorders. She is dedicated to researching and treating chronic thrombocytopenia and is involved in a clinical trial with patients with Factor 13 deficiency.

Dr. Hsieh is board certified in pediatrics and pediatric hematology-oncology. Prior to joining CHOC, Dr. Hsieh attended medical school at the Medical College of Virginia. She performed her pediatric residency and conducted her fellowship training in pediatric hematology-oncology at CHOC. Dr. Hsieh speaks fluent Vietnamese.

Research Focus

Hematology with an emphasis in Factor XIII deficiency, chronic thrombocytopenia


CHOC Clinic
1201 W. La Veta Ave. Building: CHOC Clinic
Orange, CA 92868
phone: 888-770-2462
fax: 855-246-2329

CHOC Specialty Center – Newport Beach
500 Superior Ave. 140
Newport Beach, CA 92663

St. Joseph Hospital
1100 W Stewart Dr
Orange, CA 92868


  • Medical School
    Medical College of Virginia
  • Pediatric Hematology/Oncology Fellowship
    CHOC Hospital, Orange, CA
  • Pediatrics Residency
    CHOC Hospital, Orange, CA

Academic Appointments

  • Assistant Clinical Professor
    University of California, Irvine, School of Medicine

Administrative Appointments

  • Hematology, CHOC Specialists

Professional Organizations

  • American Society of Hematology
  • American Society of Pediatric Hematology Oncology

Research Bio

Dr. Hsieh specializes in all aspects of hematology with an emphasis in Factor XIII deficiency. She is currently involved in a clinical trial with patients with this deficiency. She is also very dedicated to researching and treating chronic thrombocytopenia.

Our hematologists commonly treat:

  • Anemia, including sickle cell anemia, thalassemia, iron deficiency and lead toxicity
  • White cell and immune deficiency disorders
  • Aplastic anemia
  • Bone marrow failure syndromes
  • Thrombocytopenia
  • Vascular malformation/hemangiomas
  • Platelet disorders
  • Coagulation abnormalities, hemophilia,  Von Willebrand’s disease, rare bleeding disorders such as Factor 13 deficiency
  • Excessive clotting disorders,  thrombophilia, deep venous clots, pulmonary embolus or stroke
  • Acquired bleeding and clotting disorders
  • Prevention of bleeding and clotting problems, with particular experience for patients on cardiopulmonary bypass

  • Loan B Hsieh MD
    • Appointments:
    • Office: 714-509-8459
    • Specialty: Hematology
    • Board Certified: Pediatrics, Pediatric Hematology/Oncology
    • Additional Languages: Vietnamese
    • On Staff at: CHOC Hospital in Orange