Let your teammates know when you're being blocked on a task. Simply find the item that's blocking you, click the item to view its detail page, and then check the This is blocking me box beneath the item’s description.

Now, your team (and your Project Manager) can easily watch for places where people get blocked, in the Timelines view:

You can also filter by "Blocked" and "Blocking" in the Dashboard, Organizer, and Activity Feed:

NOTE: Before you mark an item as blocking, you must have an item assigned to you in the Someday, Backlog, or Current status.