Yes, I've never understood why the symptoms vary from day to day so much AND why some symptoms seem to disappear for awhile, then suddenly return for no apparent reason. Years ago, when I first started chiropractic treatment, my knees were very painful. They were one of the first things that greatly improved, then six months or so ago they started hurting again. Vertigo is another one that disappears for months, then suddenly returns. I sometimes feel like aliens have invaded my body!!!