Are you allergic to anything? Have you eaten anything or tried something different the last few days that you normally don't eat? It could be an allergic reaction to something you have eaten. A spice, a plant food, MSG, etc. I had a similar problem years ago and after some experimenting and eliminating foods I thought were suspect, I felt better. I eliminated soy, corn and all corn products and MSG (a preservative I think.) Be sure and read your labels and get tested for allergy sensitivity. There are many people not affected by certain foods, chemicals etc, but there are many that are. Hope this helps you.