Last night (Tuesday) he went to the Emergency Room with a possible blood clot in his arm. The pain had built up over the day, and we decided to have it checked out. He did have a clot, but it was a small one in the small vessels near the surface of his skin. Apparently this kind isn't a serious life-threatening kind because they sent him home with instructions to just apply heat pads and take Tylenol or Advil as-needed for any pain.
He took a pain pill early in the morning, but had no arm episodes, so it turned out to be a pretty good day despite the ER trip.