John Muir Health Walnut Creek Medical Center
John Muir Health Concord Medical Center
Dr. Loos specializes in head and neck surgery as well as facial plastic surgery. He works out of several BASS Medical Group offices in Contra Costa County. Dr. Loos received his medical education from Baylor College of Medicine in Houston, Texas. He completed a general surgery internship and head and neck surgery training at Georgetown University Medical Center in Washington, DC. Dr. Loos completed additional training in facial plastic and reconstructive surgery at the University of California, San Francisco. He is board certified by the American Board of Facial Plastic and Reconstructive Surgery as well as the American Board of Otolaryngology – Head and Neck Surgery. Dr. Loos’ research has appeared in medical textbooks and national scientific journals on both facial plastic surgery and head and neck surgery. Dr. Loos’ credentials include specialized experience in all aspects of head and neck surgery with additional attention to facial plastic surgery. In evaluating and treating all ages of patients, Dr. Loos focuses on delivering individualized care. While he enjoys traveling, exercise, and playing guitar, Dr. Loos most enjoys spending time with his wife, twin boys, and dog.
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!