A toxin is a harmful substance that can cause adverse effects on living organisms. Toxins can be synthetic or naturally occurring chemicals that are toxic to living organisms.

Toxins can exert their harmful effects through various mechanisms. They can disrupt normal cellular processes, interfere with the functioning of organs or organ systems, and cause damage to tissues. Some toxins target specific biological systems, such as the nervous system, cardiovascular system, or immune system. They may inhibit or stimulate certain biochemical reactions, alter gene expression, or disrupt the communication between cells.

The effects of toxins can vary widely depending on the type of toxin, the route of exposure (such as ingestion, inhalation, or injection), the dose or concentration, and the susceptibility of the organism. Some toxins can cause immediate and severe symptoms, while others may have cumulative effects over time. Toxicity can manifest as a range of symptoms and health conditions, including nausea, vomiting, diarrhea, organ damage, neurological disorders, respiratory distress, and even death.