How Traumatic Can our students be due to our "assessments"?

I have always wondered about this question as I assessed and reassessed, was assessed and reassessed, and suggested ways and techniques to assess and reassess. How deep are our students affected by OUR assessments? What are the Primary, Secondary, and even Terciary effects of these assessments? Do assessments honestly show or even qualify our students' REAL-LIFE Acquired Knowledge? Food for thought!