Charlotte and Mark discuss how Mark came to medicine out of a sense of altruism and how, after 11 years in a traditional practice, he recognized significant systems challenges for addressing chronic and complex illness within that framework. Feeling "there was more," in 2014 he started a new concierge practice, which applies a functional medicine approach -- looking at root causes for symptoms, and negotiating interventions like nutrition and lifestyle modifications best suited to the patient's needs and preferences. Mark explains how his practice allows for longer visits and greater accessibility, which foster greater trust in the patient-doctor relationship and ultimately more educated, empowered patients. He shares some of his areas of focus beyond enhanced primary care, which include: biotoxin illnesses (including tick-borne), environmentally-acquired illnesses, autoimmune diseases, gut health and anti-aging/restorative medicine. They explore the overlap between inflammation and aging, the thymus gland, immune system imbalances and some of the integrated systems that functional medicine addresses.