size of saved pdfs

Lately, when I print to .pdf or download a .pdf from an email, then open it later, it's about 1/5 the size that it should be.  I have to zoom to 200% to see the print clearly but it still does not fill the entire page.  400% is too big.  Any ideas.  I have tried everything.  I sent one of these to a client and they said they could not read it as it was too small.