Why did Walter ask Ruth what was wrong with her?
Some more clarification might be needed in this particular question. Part of the reason why Walter asks Ruth about her condition at the start of the play might be related to their general state of marriage during the exposition. Walter is immersed in a job as a driver which he detests, and yearns to open a liquor store business. Ruth, while standing by her husband, does not want to see him waste the family finances on this particular vision. Rather, she seeks to use the money to buy a home in a better neighborhood for the family. Since both of them see life in two different frames of reference at the start of the play, there might be a great deal of misunderstanding between them, prompting them to wonder why the other one is bothered or what is concerning the other.