Why does my tongue hurt when i eat orange and lemon?

Citric acid: Acidic foods may hurt or burn in your tongue is already sensitive. This could be chronic irritation from using harsh toothpaste with whiteners in it, or a yeast infection of your tongue. If it's bothering you a lot have your doctor take a look. Your dentist may be able to help you if you're due, or if you're not getting answers go see an ent.