How is illness used as a metaphor in the story, The Japanese Quince?

As a result of his alienation from the environment and Ins own humanity, a "feeling of emptiness" at times comes over Mr. Nilson. Described variously as a "queer sensation," a "faint aching just above the heart," and a "choky feeling in his throat," Mr. Nilson's ailments are the effects of a dissatisfaction with Ins life that he attempts to bury beneath order and affluence. Although he reassures himself while gazing in a mirror that his eyes exhibit "a reassuring appearance of good health," the "queer" feeling within him only increases as he enjoys the nice morning. The "emptiness Just under his fifth rib" hints at a figurative "hole in his heart," which he tries to explain away as indigestion. Mr. Tandram, who is heard coughing at the end of the story, may well be suffering the same malaise.