Internal medicine physicians are specialists who apply scientific knowledge and clinical expertise to the diagnosis, treatment, and compassionate care of adults across the spectrum from health to complex illness. At least three of their seven or more years of medical school and postgraduate training are dedicated to learning how to prevent, diagnose, and treat diseases that affect adults. Doctors of Internal Medicine can be referred to by several terms, including "internists," or "general internists." GreenField Health clinicians who are board certified in Internal Medicine include: Michael Chen, MD; Cheston Wong, PA; Dan Crawford, MD; Leesa Azar, MD; Melanie Doak, MD; Kristina Brown, DO; Jose Guillen, PA; Saga Shah, MD; Chuck Kilo, MD. 

The specialty of family medicine is centered on lasting, meaningful relationships with the whole family, from infants to great grandparents. Family physicians integrate the biological, clinical and behavioral sciences to provide continuing, comprehensive health care. Unlike pediatricians who provide care for children, and internists who provide care for adults, family medicine encompasses all ages, sexes, each organ system and every disease entity. Family physicians also pay special attention to their patients' lives within the context of family and the community.  GreenField Health clinicians who practice family medicine include: Kristina Brown, DO; Michael Chen, MD; Dan Crawford, MD; José Guillen, PA-C; and Sagar Shah, MD.

Adolescent medicine is a medical subspecialty that focuses on care of patients who are in the adolescent period of development, generally ranging from the last years of elementary school until graduation from high school or college. Adolescent health professionals also are an important clinical resource for families and youth with special health care needs and chronic illness for whom the normal transitions of puberty and young adulthood may be challenging. Adolescent medicine providers are generally drawn from the specialties of pediatrics, internal medicine, or family medicine. GreenField Health clinician Paula Koeller, MD, is certified by the American Board of Adolescent Medicine. Her practice includes patients whose ages range from 9 years old to 30 years old.

Medical Nutrition Therapy (MNT) is nutrition counseling provided by a registered dietitian. The application of MNT and lifestyle counseling as a part of the nutrition care process is an integral component of managing specific disease states and conditions.  MNT is also important for disease prevention.  GreenField Health practitioner Erin Shah, registered dietitian (RD), is licensed in the state of Oregon to practice MNT. She has completed a nutritional sciences degree, which includes a rigorous course of study in biochemistry, human anatomy and physiology, and food sciences.  Additionally, Erin has completed training in diabetes management and is a certified diabetes educator (CDE).


Physical therapy is the healthcare profession primarily concerned with addressing, and treating, musculoskeletal pain. GreenField Health has partnered with Life’s Work Physical Therapy (LWPT) to provide in-clinic services at the Westside (Barnes Road) office. LWPT therapists are experts in evidence-based manual therapy, and specialists in the evaluation and treatment of patients presenting with musculoskeletal pain. They have three publications in peer-reviewed journals for treatment of patients with chronic pain, and one publication on manual therapy for treating a patient presenting with chronic patellofemoral pain. Two therapists at LWPT have completed a fellowship in orthopaedic manual physical therapy, and are fellows of the American Academy of Orthopaedic Manual Physical Therapy (AAOMPT), an accomplishment achieved by less than 0.5% of the physical therapists in the United States. Life's Work's clinical model is geared around becoming expert clinicians with progressive mentorship opportunities and continued learning, as well as exceptional customer service and building life-long relationships with every client. Links: American Physical Therapy Association.

Eating disorders, such as anorexia nervosa, bulimia nervosa, and binge eating, are serious illnesses that can take over patient’s life, threaten their health and challenge their relationships with family, friends and colleagues. GreenField Health’s Paula Koeller, MD, is one of only a few doctors in the state of Oregon who specialize in treating patients with eating disorders. Dr. Koeller works with both adolescents and young adults up to age 30, and has particular experience with patients who are in college, either as undergrads or graduate students. “It takes strength and courage to acknowledge the ways in which an eating disorder is negatively affecting you or your loved one’s life,” Dr. Koeller says. “I, along with my health coordinator Blaine Douglas, CMA, have many years of experience helping patients with eating disorders address the physical and emotional issues underlying these conditions and move along a path to a lasting recovery.”