danMWD on "update user action hook"

Hi

Perhaps I am looking in the wrong place of the Codex but I am trying to find the "action hook" for updating a user. Instead of the action hook "user_register" I was trying to find the equivalent for when a user updates their profile/email. As with user_register I would like to access the data immediately after the user updates their details.

Is there such an action? - could someone point me in the right direction please.

Thanks.