About Dr. Diehl

Internal Medicine & Functional Medicine in Frisco, TX

Dr. Diehl

Dina Diehl, DO, is a highly trained board certified internal medicine and functional medicine specialist at Signature Internal Medicine in Frisco, Texas. She has over 15 years of medical experience as an osteopathic physician at Texas Health, Plano, as a hospitalist and outpatient internist. She has an impressive educational background.


 Dr. Diehl completed medical school at Philadelphia College of Osteopathic Medicine in Philadelphia, Pennsylvania. She then attended a residency program at Summa Health System in Akron, Ohio, and also completed some training at the esteemed Cleveland Clinic in Ohio.

She enjoys helping her patients improve their health and wellness using cutting-edge, holistic technologies and methods. Dr. Diehl uses conservative treatments for her patients whenever possible. Her caring, friendly demeanor makes them feel comfortable during each visit.

Dr. Diehl maintains her medical credentials to stay current with the latest internal and functional medicine advances. She holds medical licenses in Texas, and is a member of the American College of Physicians and Institute for Functional Medicine. 

Dr. Diehl joins only 1900 providers worldwide with a functional medicine certification. 

Functional medicine is an individualized patient-centered scientific-based approach that allows patients and the practitioner to work together to address the root cause of disease instead of just treating the symptoms and she uses this approach to promote optimal wellness. 

Dr. Diehl can evaluate your genetic, biochemical, and lifestyle factors in addition to a detailed gut microbiome analysis to direct a personalized treatment plan if desired. 

Dr. Diehl combines conventional internal medicine with functional medicine concepts to help her patients achieve the best health.

In her free time, Dr. Diehl loves spending time with her family and friends, traveling, running, golfing, and skiing, as well as watching her children’s sports games and maintaining a healthy lifestyle. 

 Dr. Diehl looks forward to caring for her patients using a concierge medicine model, allowing them 24/7 access to providers, same-day appointments, and little to no office wait times. She welcomes them to Signature Internal Medicine and enjoys exceeding their health care expectations.


Dr. Diehl's Memberships and Awards:

  • American College of Physicians
  • Member of  American Medical Association
  • Member of Institute of Functional Medicine
  • Certified Functional Medicine Provider 
  • Member of Obesity Medicine Association 
  • National Committee for Quality Assurance Excellence in Diabetes Care 2017
  • Board member at Texas Health Presbyterian, 2010 
  • Certificate of Recognition for Delivery of Quality Cardiovascular and Stroke Care 2017-2020
  • America's Most Honored Professionals 2019 - Top 5%
  • America's Most Honored Professionals 2018 - Top 1%
  • America's Most Honored Professionals 2017 - Top 5%
  • Compassionate Doctor 2015
  • Compassionate Doctor 2016
  • On-Time Physician Award - 2016
  • On-Time Physician Award - 2015
  • Patients' Choice 2016
  • Patients' Choice 2018