Dr. Mary Dea has been a Board Certified Internist since 1997. She started her career in pediatric nursing, then decided to pursue medicine. She completed medical school at Chicago College of Osteopathic Medicine, now known as Midwestern University in Downers Grove. She did a traditional rotating internship at Olympia Fields Hospital and finished her Internal Medicine Residency at Northwestern University from 1994 to 1997. Her experiences include outpatient and inpatient adult care and urgent care. Special areas of interest include heart disease prevention and allergy. She is a member of the DuPage Medical Society.

Dr. Dea's philosophy is that good mental and physical health is at the core of happiness and everyone should strive to achieve it.

Dr. Dea is a Chicago native who now resides in Naperville with her husband and two children. She enjoys jogging, volleyball, and spending time with her family. Dr. Dea speaks conversational Cantonese.