The brain goes "Whoah. This must be serious if I need this kind of reassurance. I need more of it. I need it now." And the OCD desire for certainty feeds the craving for reassurance. I used a lot of Self-Reassurance, which also overlaps with my Research Reassurance.
When I have body symptoms, and OCD is active, I will check to see if they have changed, or check both sides to see if they are the same, or poke and prod at something. It's taken an long time for me to realize that the reassurance makes the anxiety worse and puts me on red alert. Ultimately, I am gaining no useful information when I keep monitoring my body. The mole will probably look the same in 2 minutes, and this neither proves nor disproves its actual danger.
I have also conducted what Hershfield refers to as the "Mental Review"--on getting an intrusive thought about saying the wrong thing in conversation, I would go over it, retrace it, try to figure it out.
Finally, Research Reassurance is a bugger. By age 17 I was looking up medical symptoms in the health section of bookstores, and then in the reference section at my college library. This was before the modern internet, and when graphical browsers went mainstream in the mid 90's, my research took on warp speed. Researching provides the promise of finding an answer, but in the process turns up other scary things, and adds even more to obsess about. There is no website labeled "Exposure Woman: This is exactly what the problem is, and here is the solution."
I also researched my own life experience, by re-reading my old journals, diaries and correspondence, whether letters or email. One of my first Exposures in ERP therapy was putting my journals in a box on a high shelf, and learning to cope with the desire to figure out if I've always had OCD, or if I didn't try hard enough to get help, or learning to make decisions without all the "background information" my OCD thinks I need to make a fully informed choice.
Hershfield ends with a sentence that is a true sign of his clear understanding of OCD cravings to have certainty:
Finally, when it comes to resisting the wealth of information (and misinformation) available from the web and other sources, it’s best to turn the computer off altogether when you find yourself just wanting to know something “for sure.” In fact, there’s no time like the present…so let’s see if you can move on from this blog without knowing for sure if you fully understood it.