If you can try and save your work, or copy and paste into a new document and save under a new document name.

Ask someone nearby if they are having the same problem - it might be a wider network fault.

Use Ctrl+Alt+Del to see if the application is responding.

If it's not, try closing the application and re-opening it. If re-opening it seems to work, then you could try to recover a previous state of the document by following instructions found on this other FAQ.

If it's still not responding contact NUIT or ring their 24 hour hotline on 0191 208 5999.