Variables in bash can be marked so that they are set the same in any new shells that it starts; this is called being marked for export. You can have bash list all of the variables that are currently marked for export in your shell session:

$ export
declare -x EDITOR="vim"
declare -x HOME="/home/chouser"
declare -x MAIL="/var/spool/mail/chouser"
declare -x PAGER="/usr/bin/less"
declare -x PATH="/bin:/usr/bin:/usr/local/bin:/home/chouser/bin"
declare -x PWD="/home/chouser"
declare -x TERM="xterm"
declare -x USER="chouser"