You literally said that inflammation is the only disease. Those are both diseases.
Discussion
You are taking this conversation too seriously my man. The post is about chronic illness, not bacteria or viral infections.
Where do migraines fall in your grand view?
Think of disease like a tree. The external symptoms, like heartburn, are the leaf nodes. The "disease", like GERD, are the branch nodes. The underlying cause, like low stomach acid from the the standard american diet, are the trunk. Inflammation caused by industrial foods are the roots.