Although to simplify life we tell people my husband has sleep apnea, he really has difficulty breathing while lying down when he sleeps due to the diameter of his neck. The deal is his physical make-up partial blocks his airways when in a horizontal position. Prior to the CPAP, he would sleep great not snore while sitting up on the couch, but that bothered his back after awhile.
Anyway, he leanred this about himself after going through 2 sleep studies. The first was to diagnois his problem, the second was to try the CPAP machine and compare the two nights. Since having the CPAP machine, he has a more complete night of rest and I am sleeping more soundly too.
I would have your husband bring it up to his PCP and go from there. Good Luck!