Our body and mind are continually fighting against the natural order of perpetual change in our environment and in ourselves. This struggle of continual adaptation to try to keep our organism and mental construct in a state of somewhat harmonious stability and equilibrium, is what we experience as the many faces of suffering, such as stress and anxiety.
This is in a way how life is expressed and felt, through the successes and failures of this process.
Paraphrasing and interpreting Rich Hanson and Dr. Richard Mendius in The Buddha Brain, 2009 (via thetaijistudent)