Diabetes and HIV can also cause black tongue, in rarer cases. The conditions causes bad breath, a metallic taste in the mouth and a tickling feeling in the mouth. Purple tongue can be an indicator ...

A purple or bluish tongue can tongue can be a sign of poor circulation in the body. Alongside a red tongue, some clinicians ...

Diabetes patients typically have a yellow tongue, while cancer patients a purple tongue with a thick greasy coating and acute stroke patients present with a red tongue that is often crooked.