This review article discusses the toxicity, mechanisms, and health effects of various heavy metals, including arsenic, lead, mercury, cadmium, chromium, aluminum, and iron. Heavy metals are defined as metals with a specific density greater than 5 g/cm³ that can have adverse effects on the environment and living organisms. These metals can enter the environment through natural processes and human activities, and their toxicity depends on factors such as the dose, route of exposure, and duration of exposure. Heavy metals can cause a range of health issues, including oxidative stress, cellular damage, and chronic diseases. Arsenic is a highly toxic metal that can cause cancer and other health problems. Its toxicity is primarily due to its ability to interfere with cellular processes and cause oxidative stress. Lead is another toxic metal that can affect the nervous system, kidneys, and other organs. Its toxicity is related to its ability to replace essential ions in the body and disrupt cellular functions. Mercury is a highly toxic metal that can cause neurological damage and other health issues. Its toxicity is mainly due to its ability to form stable bonds with sulfur-containing compounds in the body. Cadmium is a toxic metal that can accumulate in the body and cause damage to the kidneys and other organs. Chromium can exist in different oxidation states, with hexavalent chromium being particularly toxic and carcinogenic. Aluminum is a non-essential metal that can cause neurological and other health problems, especially in individuals with impaired kidney function. Iron is an essential metal, but in excess, it can cause oxidative damage and various health issues. The review highlights the importance of understanding the sources, mechanisms, and health effects of heavy metals to develop effective strategies for their prevention and control. It emphasizes the need for public health measures to reduce exposure to these toxic metals and mitigate their adverse effects on human health and the environment.This review article discusses the toxicity, mechanisms, and health effects of various heavy metals, including arsenic, lead, mercury, cadmium, chromium, aluminum, and iron. Heavy metals are defined as metals with a specific density greater than 5 g/cm³ that can have adverse effects on the environment and living organisms. These metals can enter the environment through natural processes and human activities, and their toxicity depends on factors such as the dose, route of exposure, and duration of exposure. Heavy metals can cause a range of health issues, including oxidative stress, cellular damage, and chronic diseases. Arsenic is a highly toxic metal that can cause cancer and other health problems. Its toxicity is primarily due to its ability to interfere with cellular processes and cause oxidative stress. Lead is another toxic metal that can affect the nervous system, kidneys, and other organs. Its toxicity is related to its ability to replace essential ions in the body and disrupt cellular functions. Mercury is a highly toxic metal that can cause neurological damage and other health issues. Its toxicity is mainly due to its ability to form stable bonds with sulfur-containing compounds in the body. Cadmium is a toxic metal that can accumulate in the body and cause damage to the kidneys and other organs. Chromium can exist in different oxidation states, with hexavalent chromium being particularly toxic and carcinogenic. Aluminum is a non-essential metal that can cause neurological and other health problems, especially in individuals with impaired kidney function. Iron is an essential metal, but in excess, it can cause oxidative damage and various health issues. The review highlights the importance of understanding the sources, mechanisms, and health effects of heavy metals to develop effective strategies for their prevention and control. It emphasizes the need for public health measures to reduce exposure to these toxic metals and mitigate their adverse effects on human health and the environment.