What does it mean to have a metallic taste in your mouth and feel lightheaded?

Metallic taste on the tongue can be caused by a number of reasons: gum disease, some type of medications, some chemotherapy medications, lead and copper toxicity, ill-fitted dental appliances, and dentures with metals can also be associated. Try eating fresh yogurt because it is alkaline and stimulates the production of saliva, consume foods rich in vitamin C ; such as lemons, lime, oranges to improve your immune system and see a doctor as well for better remedies.