OCD begins with obsessions. Compulsions are actually just a monstrous side effect of OCD.
Compulsive hand-washing is hard to hide. Hoarding, definitely. Even repetitive reassurance-seeking and confession (compulsions of choice for a Pure-O) are easy to notice once someone points it out to you.
But it’s harder to see the obsessions that are driving them.
Keep reading at The Dreadful O of OCD