What’s wrong with Tom according to the dialogue?

W: Tom, does your throat hurt?
M: Yes.
W: OK. Do you want to get better?
M: Yes.
W: OK. We want you to get better, too. You’ll have your tonsils out tomorrow, and you won’t get so many colds any more.
M: But if I have my tonsils out tomorrow, I’ll miss my birthday party on Saturday.
W: I know. It’s a problem, isn’t it? Let me try to work something out.
M: What?
W: I have to think about it.
M: You’re joking with me.
W: Oh, I’m not, Tom. Give me a chance to think about it, and I’ll get a new idea.
M: A surprise?
W: Maybe. But you just put on your clothes, and I’ll think of a surprise.
M: Will it hurt?
W: No. There are other boys and girls, and they are having tonsils out. When we get there, you’ll see them operated courageously.
M: I don’t want to.
W: Change your clothes, Tom. Everything will just be fine.