What Is The Treatment For Nausea And Headache?

my husband has severe cad and lately has been experiencing severe nausea , slight headache and generally not feeling well but in eposides not all the time. He sometimes feels tightness but not really chest pain. He has had a 5 vessel bypass 13 years ago, two stents in the grafted arteries 2 years ago , one restent 18 months ago which was preceded by a moderate heart attack. At this time he was also told he had 6 other blockages with between 50 and 65%