Occasionally Microsoft Word documents may suddenly increase in file size from say 1mb to 23mb. To correct the majority of problem files; the simplest way is to ensure that ‘Save Preview Picture’ is unchecked in the properties dialog box when saving your document.
In addition:
• Turn off ‘Allow Fast Saves’ under tools/options/save
• Turn off ‘Automatically save version on close’ under file/versions
Failing the above changes to the Document Structure, final possible solution is to copy the contents into a new document with the above options.