Can a ganglion cause numbness in arms?

U*nlikely: If ganglions occur within the carpal canal it can cause you to develop carpal tunnel syndrome, numbness in the thumb and fingers supplied by the median nerve. But not the arms. Could also effect the ulnar nerve if ganglion occurs in guyons canal. If you have numbness in the arms you should seek evaluation with a neurologist.

Yes: Ganglions are soft tissue masses that may occur in any joint, but most often occur on or around joints and tendons in the hands or feet. If a ganglion is associated with or adjacent to a nerve, it can cause compression or irritation of that nerve, through mass effect, which may result in numbness, tingling and/or pain.

A ganglion or other : Mass can press on nerves and rsult in numbness or motor weakness but this is uncommon. Classic locations for this occuring is at the ulnar nerve at the wrist in a region known as guyon's canal. By arm if you mean the upper arm or the forearm while any mass or cyst has the potential to do this it is not very common. More likely are 2 independent problems ie having a ganglion and carpal tunnel.