Lisa, I only have had my shunt to over drain a couple times. Both times, it was remedied by implantation of an anti-siphon valve. Best I remember (yes, my memory stinks too), the symptoms were amplified, especially the headaches. During the week or two prior to surgery, I honestly thought my head would explode but, with the over-draining headaches, it seemed as they were more "localized" and sporadic. In my opinion, these were more of a piercing pain, as opposed to the widespread, dull ache, and at times would bring me to my knees. If the headache subsides, or better yet goes away while laying down, this is a good indication of over-draining.