I Am Curious Both My Hubby And I Are Having

I am curious both my hubby and I are having night sweats (not every night but frequently) and feel blah the next day. Hubby getting blood work this week but I just got a clean bill of health this past month. Not actually feeling sick, just the night sweats and nausea. We have the symptoms the same nights/days and feel fine all the rest of the time. I have RA and my hubby has hep c (no viral count). What could be causing these symptoms. All other blood work is good.