This problem occurs because Microsoft Word automatically applies Heading styles to the text in your Word document. Some of these styles are also used to format text when it is displayed in an HTML page, and when they are converted to HTML, your browser automatically applies text and paragraph formatting that might vary from how it appears in Word.
Resolve this problem by modifying the style setting for the affected text in your Word document and re-upload the file. Do this by highlighting the affected text and changing it using one of the methods below: On the top toolbar, choose a style other than a Heading from the dropdown list. Click Apply. You can also select the text, right-click on the text and select the correct style from the 'Style' menu.