Are you talking about an arm or leg or both?
Do you notice any discoloration between the two sides?
ANy pain or numbness?
For how long has this been going on?
This is a little unusual to be both upper and lower extremities.
Typically we look for circulation issues. Pulses equal,any color changes, etc. If those are normal then we think of nerve compression.
With Nerve compressed there is usually accompanying numbness, pain of varying degrees, muscle mass differences, etc.
But not all symptoms need to be present for either condition to be there.
So, your question was what to ask your provider about...
1 - Be sure to tell him how bothersome it is, any changes you notice. IF you have any weakness on that side compared to the other or decreased grip or leg not as strong, etc.
2 - Ask if he thinks it is a circulation issue or a nerve issue.
3 - If he does not address the issue to your satisfaction you could ask to be referred to a neurologist. They would be a good place to start.
SO the main thing is to tell him specifically your concerns and any changes you have noticed. Make your appointment for just this one thing, It will take time and a whole office visit to just address this issue. I would encourage you not to see him for other reasons and then say "Oh, by the way...". We tend not to have the time to really focus on the "by the way or while I am here" complaints. :)
Again it is unusual for it to be both extremities, Sometimes it can be due to a history of trauma of the neck/shoulder for the arm - lower back/hip for the leg.
With it being both arm and leg, one may consider compression on the nerves effect that side of the body which would be in the head. That is why a neurologist would be helpful.
It is difficult to say without a very through exam and putting all the findings together.