Our Physician

Dr. Robert O'Brian, M.D

Rheumatologist

A native of Seattle, Washington, Dr. O’Brian proudly served in the U.S. Navy with assignments on both coasts and deployments to Afghanistan, the Mediterranean, Central and South America, and Guantanamo Bay, Cuba. He spent many years training and practicing at Walter Reed National Military Medical Center in Bethesda, and now calls Maryland home.

Dr. O’Brian lives with his wife, Laura, and their two children, Oscar and Emerson, and values the strong bonds of his close-knit family.

“I feel privileged to have been able to participate in the care of so many wonderful patients over my years in the Navy. My goal has always been to provide the highest level of compassionate and comprehensive care—the same care I would give to members of my own family.”

Dr. O’Brian brings a wealth of experience, empathy, and dedication to every patient interaction, combining military precision with a deeply personal approach to rheumatology.

Mirza Humayun Beg, MD

Board-Certified Rheumatologist

Dr. Mirza Humayun Beg is a board-certified rheumatologist with more than 15 years of experience diagnosing and treating a wide range of autoimmune and musculoskeletal conditions, including rheumatoid arthritis, lupus, psoriatic arthritis, gout, osteoporosis, and other inflammatory disorders. He is dedicated to providing compassionate, evidence-based care tailored to each patient's unique needs.

Throughout his career, he has practiced in leading healthcare organizations across Texas, California, Illinois, and West Virginia, while also holding academic appointments at respected medical institutions.

He completed his fellowship in Rheumatology at the University of South Florida and is board certified by the American Board of Internal Medicine in Rheumatology. Dr. Beg is a Fellow of the American College of Rheumatology and remains actively involved in clinical research and medical education, contributing to advancements in the diagnosis and treatment of rheumatic diseases.

Dr. Beg is committed to helping patients improve their quality of life through personalized treatment plans, patient education, and the latest advances in rheumatologic care.