Chelation therapy is the administration of chelating agents to remove heavy metals from the body. Based on speculation that mercury poisoning may trigger the symptoms of autism, chelation therapy is often used to treat autism, with some surveys suggesting 2–8% of children with autism have had the therapy.
When indicated, toxins and/or heavy metals can be removed by increasing the activity of the immune system; increasing the pathways which are responsible for elimination of toxins. Chelation is the process of introduction of a substance, by oral, rectal, trans-dermal or intravenous means which binds a heavy metal and enhances its elimination.
Alternative medicine uses chelation therapy as a non-standard treatment for some ailments, including autism, heart disease, kidney dysfunction, calcific band keratopathy (an eye disorder), and ovarian cancer.