John Muir Health Walnut Creek Medical Center
Surgical Critical Care
Dr. Diaz is a trauma and acute care surgeon with specialty training in surgical critical care. He was born and raised in Monterrey, Mexico and attended medical school at Monterrey Tech School of Medicine in his hometown. After that he obtained an MPH in Quantitative Methods from the Harvard School of Public Health and went on to work as a research assistant at the Harvard Center for Surgery and Public Health for a year. During this time, he participated in research related to improving outcomes in surgery, specifically, efforts to prevent surgical errors. In 2008, he did his general surgery internship at Brigham and Women’s Hospital in Boston and then transferred to the University of Texas Health Science Center at San Antonio for the rest of his general surgery residency. During this time, he realized the challenges of trauma surgery and the satisfaction of helping patients through such trying times were his passion. He then completed a Surgical Critical Care fellowship at UTSW in Dallas. He stayed on for an additional year as an assistant instructor and trauma fellow to get as much experience as possible from the very busy Rees-Jones Trauma Center at Parkland. In 2018, Dr. Diaz and his wife, Dr. Yanett Anaya, who is a reproductive endocrinologist that trained at the University of California San Francisco, moved to the Bay Area so that she could return to UCSF as an assistant professor and he could join BASS Medical Group as a trauma and acute care surgeon. Dr. Diaz is board certified by the American Board of Surgery in both General Surgery and Surgical Critical Care and is a member of the Eastern Association for the Surgery of Trauma and the Society of Critical Care Medicine. Outside of the hospital, Dr. Diaz enjoys spending as much time as possible with his wife and their dog, Charlie.
Dr. Audrey "Lisa" Arzamendi is double board-certified in internal medicine and endocrinology. Since 2012, she has specialized in diabetes, obesity and metabolism, thyroid disease (including Hashimoto's and Graves'), polycystic ovary syndrome (PCOS) and sex hormone disorders, adrenal and pituitary dysfunction, osteoporosis, parathyroid/calcium disorders, and thyroid and parathyroid nodules and cancers. She is highly trained in ultrasound-guided fine-needle aspiration (FNA) biopsy of the thyroid (99% diagnostic rate).
Dr. Arzamendi is committed to safe and established medical treatments, and prides herself on staying informed about emerging therapies and research-supported non-prescription options. She is experienced working with all forms of brand-name and generic thyroid medications, and as a type 1 diabetic herself, has first-hand knowledge of nearly all available prescription and technological diabetic treatments, to best support patients in selecting their optimal diabetes treatment regimens.
Dr. Arzamendi graduated with honors from Stanford University, with a BA in Human Biology and a concentration in Health & Human Performance. She attended UC San Diego School of Medicine (receiving a federal NIH National Cancer Institute fellowship), and completed her internal medicine residency at Kaiser Pemanente’s Santa Clara Medical Center. Her endocrinology training was completed at UC Davis Medical Center. She previously practiced in California's South Bay before relocating to open her practice in Walnut Creek in 2020. Dr. Arzamendi was a Stanford varsity athlete and still enjoys running, hiking, tennis, rowing, and other outdoor activities. She loves spending time with her husband and many pets, and looks forward to being your doctor!
Medical School: Monterrey Tech School of Medicine
Internship: Brigham and Women’s Hospital in Boston, Massachusetts
Residency: University of Texas Health Science Center in San Antonio
Fellowship: University of Texas Southwestern Medical Center in Dallas