It may be that there is something wrong with the mobile phone case, which is caused by using some unqualified paint and waste.

Or playing mobile phone for a long time, fingers and hands can't get a rest.

Insufficient local blood supply and poor blood circulation can cause local oppression. Playing mobile phone for a long time is easy to cause poor local blood circulation. I suggest you take a rest, don't always be a low-headed person, exercise regularly, and exercise your neck, so that you can supplement calcium properly.