Sometimes when viewing a constituent record you will not see all of the fields that should be there.
You can customize your profiles through the Setup>Standard Page Center. Sometimes fields appear to be hidden because that page needs to be updated. To update the page go to Setup>Standard Page Center and customize the admin side profile page.
Note that if you have Multicenter, each center has its own set of standard pages. To go to those pages, you have to switch to that center and then follow the same steps as above.