Reports hand pain while holding a phone and perceived improvement when no longer holding it.

I notice that when I have my phone in my hands for any length of time, over 30 minutes, my hands begins to ache. I am over 60 so I use to attribute it to simple arthritis but when I don’t use my phone, my hands are fine. First thing in the morning I notice it most. Maybe because I have just awakened and should be rested.