Why does my husband snore all of the sudden? he didn't until just recently.

Several thoughts: Several thoughts, recent weight gain, worsening nasal obstruction, recent cold or flu. Snoring occurs when something between the lips/nostrils and the windpipe interferes with air flow. If your husband never snored before and is now that something should be evaluated. He can try a breathe-right strip and see if it helps. If it does it probably is his nose. An ENT doctor can easily evaluate him.

New Snoring: New snoring means new blockage of the airway. Snoring is about turbulent airflow through partially blocked airways. A stuffy nose, enlarged tonsils, recent weight gain, worsening acid reflux, a head cold -- all could contribute to new snoring. See an ENT doctor.