You have to understand about my dad, that he was once a very stout workhorse of a man and is not really prepared to cope with being 82 and barely able to lift his own arms. Besides being worried about mom for her own sake, I expect that some of his anxiety comes from the fact that he depends on her for so many of his own physical needs. He is long-used to the role of the provider -- when forced into a role where he's more dependent, he doesn't know how to act. He's certainly not going to say to my mom, "I'm very worried about your health because you won't get out of bed." That kind of direct communication is foreign to him. So he demonstrates it by gesture -- "if you won't get up, I'll call John at you" so to speak. :)
What really got me was that he began to get emotional over the phone. This is my dad, the super-reserved man who sits quietly in the corner and never says anything unless it's the perfect one-word snark. The 1974 edition of the New World Dictionary, under the entry "laconic," had a photo of my dad. When he reaches the point of being demonstrably upset, that is the equivalent of other people wailing and gnashing their teeth.
So I'm worried that the anxiety of getting old is wearing on him. On top of having trouble walking, and on top of the fear of taking yet another nasty fall, on top of the pain-in-the-ass of going to the doctor twice a week and living mostly on pills, he's also trying to come to grips with not being Iron Man any more, and with the knowledge that at 82 he's reached the Sword of Damocles age. He's got a lot to carry, my dad has. Really I'm honored that when he needed somebody to help with the load, he called on me.
Anyway, I talked to mom and made sure she was all right, and I talked to dad and helped get through to him that mom would be okay with a little rest, and told them we'd go and have dinner with them tomorrow to check in on them and generally make sure all was well; they both seemed perked up by that. Compared to what they're dealing with, my own neuroses can easily take a back seat for a while.