My mouth is sore. My inner parts of my mouth around the lips, tip of tongue, gums..and my gums are really bright red and my mouth is very dry. They don t itch at all; just sore. What is it? It began Thursday night into Friday morning. It s not gotten any worse or better. I am swishing warm salt water around in my mouth. The only new food I ate that day was yam biscuits made of yams, flour, baking soda, baking powder butter and milk.