John Muir Health Walnut Creek Medical Center
John Muir Health Concord Medical Center
Dr. Michael Kassels is an internal medicine specialist who practices in both Concord and Brentwood. Dr. Kassels specializes in managing chronic illnesses, diagnosing, and helping promote health and disease prevention. He treats both adolescents and adults who have everything from simple colds to complex conditions. Dr. Kassels also has a special interest in the evaluation and treatment of sports medicine injuries and has worked with the San Diego Chargers, the U.S. Ski Team, the Phoenix Suns and the San Francisco 49ers. A few of the conditions Dr. Kassels treats includes: Chronic illnesses Diabetes Hypertension High cholesterol Asthma Viruses and infections Depression and anxiety Rashes Bipolar disorder Aches and pains Muscle sprains and strains Back pain Dr. Kassels is the founder and director of Diablo Valley Specialists, which he opened in 1992. He is a diplomate of the National Board of Osteopathic Medical Examiners. He is also a member of the American Medical Association and the American College of Physicians. In 2015, Dr. Kassels merged his practice with BASS Medical Group. Dr. Kassels received his medical degree from the College of Osteopathic Medicine of the Pacific in Pomona, California. He completed both internship and residency training at Kaiser Permanente Oakland Medical Center. Dr. Kassels is fluent in both English and Spanish.
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: Western University of Health Sciences in Pomona, California
Internship: Kaiser Permanente Medical Center in Oakland, California
Residency: Kaiser Permanente Medical Center in Oakland, California