Reactive oxygen species (ROS) are highly reactive molecules that contain oxygen. They are produced naturally in the body during processes like metabolism and can also arise from environmental factors such as pollution and radiation. While ROS play a role in cell signaling and immune responses, excessive amounts can lead to oxidative stress, damaging cells and tissues. Oxidative stress is linked to various health issues, including cancer, cardiovascular diseases, and neurodegenerative disorders. The body has defense mechanisms, such as antioxidants, to neutralize ROS and maintain balance. Understanding ROS is crucial for developing strategies to mitigate their harmful effects.