Symptoms of heavy metal poisoning include gastrointestinal distress such as nausea and diarrhea, as well as neurological symptoms such as numbness in the limbs and loss of mental function, states the National Organization for Rare Disorders. The symptoms of heavy metal poisoning vary greatly depending on the particular metal involved.
Relatively common types of heavy metal poisoning include arsenic, cadmium, chromium, lead and mercury, according to the National Organization for Rare Disorders. Metal poisoning can also be caused by gold, silver, tin, lithium and copper. Arsenic can cause brain damage, as well as damage to peripheral nerves, along with striped fingernails, edema, vomiting and bloody diarrhea. Lead poisoning also causes brain damage and can lead to seizures, high protein in the blood and anemia. Mercury poisoning causes neurological symptoms such as excitability, loss of memory and irritability, and can cause permanent brain damage.
Many metals are actually necessary nutrients at low levels, but when they begin to build up in the tissues, they can become toxic, explains the National Organization for Rare Disorders. Necessary metals that can cause poisoning include iron, zinc, manganese, copper and chromium. Any of these metals, when taken in excess, can displace other essential minerals in the body and cause alterations in function.