There really isn't much pain, it's more of a phantom ache that crescendos if I try to move my arm laterally to the left. In fact, there are a few movements that my body is not allowing me to do at all with my left arm. What started as an irritation this morning thrummed its way up to a full-blown annoyance by the time I got home and could take some ibuprofen.
I've had this problem before with it getting bad enough that I saw a doctor the last time. Based on that experience, it's just a matter of resting it and getting the inflammation down so that the nerve doesn't have so much pressure on it. Hopefully, a good night or two of sleep will have it working properly again.