U was extremely happy having been referred to Dr. Santiesteban after having seen two other providers who clearly missed a very serious diagnosis that very much could have been life threatening! This Dr is very intelligent and very well trained! He seems to truly know medicine and was able to catch and correct my medicines and get me appropriate treatments. I am fortunate and blessed to have been referred to him. While the front line office staff is nice to find happy and efficient but we all know that is a gamble as such help changes and is always shifting, but if you are more interested in strong medical advice and expertise, I would highly recommend Dr. Hector Santiesteban. His demeanor is kind and he is very attentive. Yes, busy because he is well sought after but once you get into his office, he dies make you feel as though you are top priority. I was also surprised to find out that he double board certified in internal Medicine and the speciality of Nephrology where he has practiced for over 20 years and trained other MD at UCSF Medical School. Overall, I was very happy with his care!