I’m sure someone can help me identify this story I read in the late-seventies, probably in an anthology of sci-fi stories. Because of the way Mars and Martian civilization is described, I would guess this is probably a story from the 1940s or 50s, or possibly even earlier.
A human doctor (maybe a Martian specialist?) wants to help an old friend, a Martian who has come down with a critical illness.
I don’t remember many details or much dialog from the story, but I seem to remember at some point the friends are talking about how much Martian and Human cultures had learned from each other. The Martian talks about how, although Mars has highly advanced sciences, they had no medical profession of their own. The idea of medicine had simply never occurred to them.
Although he wants to help, and promises his friend he will travel to Mars to treat him, the human doctor finds he cannot leave his home. He learns that he himself apparently suffers from some sort of psychosomatic condition that makes it impossible for him to travel.