There are a lot of potential problems here.
Sleep apnea. This needs a sleep study.
Buzzing in the ears is tinnitus: this can be from an ear problem, a brain problem, or vascular problem, a problem with the blood vessels.
Also, she needs an EKG, and heart exam.
Apparently she has not seen a doctor and she needs a geriatric asessment.
A holter monitor is needed as well, to see what the heart is doing.
Thyroid can be screened, but with hypothyroid the heart is usually not pounding. With hyper, there is usually diarrhea, tremor, etc.
I am a double board certified, US doctor.
Talk to me, DR. Thomas, for all your medical questions.
I am here by request daily.
Please click a positive rating on this post.