upper arms are always hurting

[Tazz]

rest it up and take it easy

 

[MasonicBodybuilder]

Switch to dumbbells and do lighter weight

 

[Chez21]

Most people I know overtrain their arms then lift improperly when doing chest/back. Hence putting more strain on bis/tris even on off days. You really have to focus on using only chest or back when lifting those and possible cutting out arm days altogether