Ivan turgnev explores the basic human nature. It's need for love, connection with fellow human being, despair, trying to understand logically. A doctor fell in love with his dying patient. His patient whether loves him truly or not is not important because they can never be together.
Story leaves many answered questions.
He opens his heart to another patient of his with whom he has no acquaintance. Why he felt he could trust the author? Why he married to a ill tempered woman?
The author expresses the innermost feeling of human mind. What goes on, how one's feels. It's like reading your own thoughts.