Can a pinched nerve cause numbness in your hand and forearm?

Sure it can: Depending on the location and severity of the impingement, a pinched nerve in your neck can certainly cause symptoms along its path--as seen example picture here. A pinched/trapped nerve at the elbow behind your funny bone can do so as well, so is carpal tunnel syndrome. If symptoms bothersome, consult doc for evaluation/treatment. Good luck.

Nerve compression &: Yes, nerve compression & many other things. Carpal tunnel is common but dont assume its that just because its is frequent..See a hand surgeon.