Dark tongue discoloration

Symptom

Toxic heavy metals: Toxic heavy metals are behind the tongue discoloration when it's dark gray or black. Every single human being on planet Earth has toxic heavy metals inside of them - in their brain, liver, spleen, pancreas, intestinal tract lining, bones, and eyeballs.
Metal oxidation and spillage: Toxic heavy metals that have oxidized over the years that have been hidden away deep in pockets inside the liver and other places in the body decide to spill over. This is overflow when the body is finally at its tipping point - a spill when tissue in the body or an organ decides to dump its storage because storage banks were filled.