Poisons are substances that can cause harm or death when they enter the body. They can be found in various forms, including liquids, solids, and gases. Common examples of poisons include carbon monoxide, arsenic, and certain plants like poison ivy. The effects of poisons depend on the type, amount, and method of exposure. Many poisons disrupt normal bodily functions by interfering with cellular processes or damaging tissues. Symptoms of poisoning can vary widely, ranging from nausea and headaches to severe reactions like organ failure. Treatment often involves removing the poison from the body or using antidotes to counteract its effects.