There are two ways for users to "hide" on Facebook. They may have set their profile to private, so it does not show up on Facebook's people search, or they may have been "hidden" from your news feed in order to stop their statuses from showing up on the feed. The private users can only be found by utilizing Facebook's personal URL feature. Friends hidden from the news feed can be uncovered in the Facebook options.
Log into Facebook.
Enter the person's personal URL in the URL bar on your browser. To obtain this URL, you will need to get it from the person who owns the profile or a friend who is friends with the user. The personal URL is the text displayed in the URL bar when that profile is open. If the person has created a username, it will be www.facebook.com/[username], where [username] is the name.
Remove hidden status updates by clicking "Edit Options" at the very bottom of the feed. Click the "X" next to a user's name to show their posts.