Photo Editing

I am using MGI PhotoSuite III to edit old pictures to remove stains, creases etc and saving the result in a .TIF file. The original picture was scanned and saved as a .TIF file. The original scanned in picture before editing was 46.7Mb. After editing the saved .TIF file was then 146Mb. How could such an increase in size happen and will that be a problem when trying to have a 5×7 photograph printed at photo shop?