What is Oxidative Stress and Should You Worry About It? Nadine Jolie Courtney Replay Video What is oxidative stress? Whether you're focused on your skin or your general health, you've no doubt heard the terms antioxidants and free radicals before. But the concept of oxidative stress may be less familiar. "Oxidative stress is an imbalance between antioxidants and free radicals in the body," explains Niket Sonpal, MD, an internist and faculty member at Touro College of Medicine on New York City. When free radicals outnumber antioxidants, your health is at risk. "Free radicals are significant because they can cause a huge domino effect. They react so easily with other molecules. When this occurs, it is called oxidation. This can be harmful or beneficial to the body," Dr. Sonpal says.