Preface The roles of Nurse Practitioners (NPs) and Physician Assistants (PAs) have become more important than ever in today's rapidly evolving healthcare system. At Wynn Medical Center, we have seen firsthand how well-trained NPs and PAs can transform patient care, improve access, and strengthen physician-led collaborative practice models. Through years of clinical teaching and interdisciplinary training, our mission has been to help develop confident, compassionate, and evidence-based NP/PA providers. This book was created as a practical guide for NPs and PAs managing common conditions encountered in everyday outpatient practice. Across 23 chapters, readers will find concise, clinically focused approaches to the NP/PA professions in internal medicine, psychiatry, women's health, pediatrics, rheumatology/dermatology, and preventive care. I sincerely thank my colleagues, physicians, NPs, PAs, pharmacists, educators, students, and healthcare professionals whose contributions made this textbook possible. Huynh Wynn Tran, MD, FACP Associate Professor of Medicine and Pharmacy Founder/CEO of Wynn Medical Center Clinics, Los Angeles, USA