Poisoning refers to the process by which a substance is introduced into the body, causing harm or injury. This can occur through ingestion, inhalation, absorption, or injection of the poisonous substance. Poisoning can result from exposure to chemicals, heavy metals, radiation, biological agents, or even certain foods and medications. The severity of the effects depends on factors such as the type and amount of the substance, the route of exposure, and the individual's susceptibility. Treatment for poisoning may involve supportive care, administration of antidotes, or other interventions to mitigate the damage caused by the toxic substance.