Interesting...
[arms get heavy also when using them especially when i have to raise them to work on something overhead like changing a light bulb in a ceiling fan. My hands also cramp up if i use them too long.]

That sounds like a blood flow issue that many with Thoracic Outlet Syndrome have..
Roos test..
Cold and Tingly Hands/Positive ROOS Test - YouTube
Shoulder - Orthopedic Tests - Physical Therapy Web

But...
*I think I read approximately 25% of people will have a positive Roos test without having actual TOS.
Proper head, neck, shoulder alignment may help with the issue..
Slumping or forward head or shoulders compresses the area.
upper body posture assessment - Google Search

If you have done a lot of desk or forward leaning/overhead activities, repetitive motions, it could be related to that factor..
We have more information on our TOS forum sticky threads.


I am curious if others with PN have similar arm heaviness/blood flow issues..