Oxidative stress is defined as an imbalance between the production of reactive oxygen species (ROS) and the biological system's ability to detoxify these reactive intermediates or repair the resulting damage, leading to the disruption of redox signaling and molecular damage to proteins, lipids, and DNA. This condition arises when free radicals—unstable molecules with unpaired electrons—exceed the body's antioxidant defenses, which normally neutralize them to maintain cellular homeostasis.

While ROS are naturally produced during normal metabolic functions and play roles in cell signaling and immune defense, excessive levels caused by factors like aging, environmental exposures (pollution, UV radiation, toxins), poor diet, and chronic inflammation can cause significant cellular harm. This damage is implicated in the development of various chronic conditions, including cancer, Alzheimer's disease, Parkinson's disease, heart disease, atherosclerosis, and diabetes.

Diagnosing oxidative stress directly is challenging because there are no specific clinical symptoms; however, it is often associated with signs like chronic pain, inflammation, and wrinkles. Medical assessment typically relies on biomarkers that detect oxidative modifications, such as:

• Lipid peroxidation markers like isoprostanes and malondialdehyde.

• Protein oxidation markers including carbonyl formation and tyrosine modifications.

• DNA damage markers such as 8-hydroxy-2'-deoxyguanosine (8-OHdG).

• Redox status indicators like the GSH/GSSG ratio.

Management focuses on reducing free radical production and boosting antioxidant capacity through dietary changes (consuming colorful fruits, vegetables, nuts, and seeds), adequate sleep (7–9 hours) to support the brain's glymphatic system, and minimizing environmental exposures like UV rays and pollutants. Some short-term oxidative stress may even be beneficial, inducing a process called mitohormesis that helps prevent aging and initiates stress response mechanisms.