I have had periodic tinnitus in my left ear for maybe 10 years and I'm 55. I would say that it "comes and goes" after sleeping. Rarely have I noted it going away or coming back while I'm awake.

I have some high frequency hearing loss in this ear, probably due to using noisy machinery in my 20s without proper hearing protection. Anytime I do loud things nowadays, I wear hearing protection.

I have noticed my tinnitus seems less frequent if I stay properly hydrated. I have a tendency to forget to drink water and making a point of it seems to help.