This review article discusses the toxicity, mechanisms, and health effects of various heavy metals, including arsenic, lead, mercury, cadmium, chromium, and aluminium. Heavy metals are naturally occurring elements with high density, and they can be harmful to humans and the environment when present in excessive amounts. These metals can enter the environment through natural processes and human activities, such as mining, industrial waste, and agricultural practices. Once in the environment, they can accumulate in the food chain and cause long-term health effects. Heavy metals can cause toxicity through various mechanisms, including oxidative stress, disruption of cellular processes, and interference with essential biological functions. For example, arsenic is a toxic metal that can cause cancer and damage to the nervous system. Lead is highly toxic and can affect the nervous system, kidneys, and other organs. Mercury is a neurotoxic metal that can cause damage to the brain and nervous system. Cadmium is a toxic metal that can cause kidney damage and bone disorders. Chromium can cause damage to the kidneys and lungs, while aluminium is associated with neurological disorders and Alzheimer's disease. The health effects of heavy metals can vary depending on the type of metal, the dose, and the duration of exposure. Chronic exposure to heavy metals can lead to serious health problems, including cancer, neurological disorders, and organ damage. The review also discusses the sources of heavy metal exposure, such as industrial emissions, contaminated water, and food, and the measures that can be taken to reduce the risk of heavy metal toxicity. Overall, the review highlights the importance of understanding the mechanisms of heavy metal toxicity and the need for effective prevention and treatment strategies to mitigate the health risks associated with heavy metal exposure.This review article discusses the toxicity, mechanisms, and health effects of various heavy metals, including arsenic, lead, mercury, cadmium, chromium, and aluminium. Heavy metals are naturally occurring elements with high density, and they can be harmful to humans and the environment when present in excessive amounts. These metals can enter the environment through natural processes and human activities, such as mining, industrial waste, and agricultural practices. Once in the environment, they can accumulate in the food chain and cause long-term health effects. Heavy metals can cause toxicity through various mechanisms, including oxidative stress, disruption of cellular processes, and interference with essential biological functions. For example, arsenic is a toxic metal that can cause cancer and damage to the nervous system. Lead is highly toxic and can affect the nervous system, kidneys, and other organs. Mercury is a neurotoxic metal that can cause damage to the brain and nervous system. Cadmium is a toxic metal that can cause kidney damage and bone disorders. Chromium can cause damage to the kidneys and lungs, while aluminium is associated with neurological disorders and Alzheimer's disease. The health effects of heavy metals can vary depending on the type of metal, the dose, and the duration of exposure. Chronic exposure to heavy metals can lead to serious health problems, including cancer, neurological disorders, and organ damage. The review also discusses the sources of heavy metal exposure, such as industrial emissions, contaminated water, and food, and the measures that can be taken to reduce the risk of heavy metal toxicity. Overall, the review highlights the importance of understanding the mechanisms of heavy metal toxicity and the need for effective prevention and treatment strategies to mitigate the health risks associated with heavy metal exposure.