The dilutional pseudoanemia seems a little sketch to me. The only way rehydrating would cause this on a CBC is if you just got rehydrated and then immediately drew some blood and checked it. It seems to me that if you actually did get dehydrated enough to cause hemoconcentration, if you immediately drank enough to actually overhydrate and dilute out your blood, the compensatory mech. of your body would handle that pretty quick and your Hct would go back to normal before you would get to a Dr. and have it checked. The Hct "normal" levels are not for 100% of people. Granted, they do fit almost all people, you may just not normally be in that range all the time. Unless it is actually affecting your day to day life and exercise routine or keeps dropping lower and lower, I don't see it being a significant problem. Obviously, keep checking it to be sure though.