Hi Catherine,
Welcome to the Analytics Community!
Normally when a segment gets updated, the workspace project gets updated just after you save it.
If that doesn't happen, you can go to Project Menu and click on 'Refresh project'. It will update all changes that you have made.
I hope that helps. Also, please introduce yourself to our community members - http://help-forums.adobe.com/content/adobeforums/en/analytics-forum/adobe-analytics.topic.html/forum...
Thanks,
Tanmay