Heavy metals such as mercury, lead, chromium, cadmium, and arsenic are toxic to humans and can cause various health issues. These metals are commonly found in the environment and can be ingested through food, water, or air. Their toxic effects include damage to the nervous system, kidneys, liver, and other organs. The mechanisms of toxicity involve oxidative stress, enzyme inactivation, and DNA damage. Mercury can cause neurological and kidney damage, while lead can lead to anemia and damage to the nervous system. Chromium is a known carcinogen, and cadmium can cause kidney and bone damage. Arsenic is also a carcinogen and can cause various types of cancer. The toxic effects of these metals can be acute or chronic, and their mechanisms of action are similar, involving the generation of reactive oxygen species (ROS), weakening of the antioxidant defense, and DNA damage. The toxic effects of these metals can be mitigated through chelation therapy. The study reviewed the toxic mechanisms of these five heavy metals and their effects on the human body.Heavy metals such as mercury, lead, chromium, cadmium, and arsenic are toxic to humans and can cause various health issues. These metals are commonly found in the environment and can be ingested through food, water, or air. Their toxic effects include damage to the nervous system, kidneys, liver, and other organs. The mechanisms of toxicity involve oxidative stress, enzyme inactivation, and DNA damage. Mercury can cause neurological and kidney damage, while lead can lead to anemia and damage to the nervous system. Chromium is a known carcinogen, and cadmium can cause kidney and bone damage. Arsenic is also a carcinogen and can cause various types of cancer. The toxic effects of these metals can be acute or chronic, and their mechanisms of action are similar, involving the generation of reactive oxygen species (ROS), weakening of the antioxidant defense, and DNA damage. The toxic effects of these metals can be mitigated through chelation therapy. The study reviewed the toxic mechanisms of these five heavy metals and their effects on the human body.