Should I be worried...?

BOTH!

I'm sorry... What's wrong with him?

你 should think of him and be happy for him

Worrying about him won't help whatever is wrong with him. But 你 don't need to fake smile either. Ask your parents 或者 even his doctor if there is anything 你 can do to help him when he's released from the ICU.

Follow your heart.

Talk to family and 老友记 about it, i'm sure he will be ok.
Sorry i don't have the best advice...

Just 显示 your true feelings- if 你 think that your feelings are too sad, then try your best to cheer yourself up and think positively, and hopefully that will reflect on your whole family :)

If 你 aren't worried 或者 upset don't pretend to be, just don't be mean 或者 in-sensative. Just do whatever 你 think is right don't pretend 你 feel one way if 你 feel another. btw sorry if I sound mean 或者 anything, but why is ur brother in intensive care. (If 你 don't want to say 你 don't have to, 你 could always 收件箱 me otherwise if 你 don't want everyone to see. Anyway if 你 can't say I'd understand)

Be realistic about it, but not too realistic. Be as optimistic as u can about it. Having an optimistic attitude will help u be happier,and there's still hope for him. And also, if u feel like crying, then cry. U sometimes just need to let it out. :) I hope this helps.

The best thing 你 can do for him is pray for him and be there for him.

I hope he gets better soon:)
Try and be optimistic, positive thoughts always help.
(I'm not very good at giving advice)

你 shouldn't be worried about what's wrong with him, just don't try to be sarcastic with you're smiles.