How do I insert expanders?

[patcie]

For example if I type bp I want it to come out as blood pressure.

 

[Barry Schwarz]

For example if I type bp I want it to come out as blood pressure.

Look at the features available on the AutoCorrect tab of
Tools -> AutoCorrect Options...

 

[Fumei2 via OfficeKB.com]

Or...make an AutoText of "blood pressure", with a name of "bp".

AutoCorrect may be easier though.