Should I be worried...?

BOTH!

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

آپ should think of him and be happy for him

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

Follow your heart.

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

Just دکھائیں your true feelings- if آپ 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 آپ aren't worried یا upset don't pretend to be, just don't be mean یا in-sensative. Just do whatever آپ think is right don't pretend آپ feel one way if آپ feel another. btw sorry if I sound mean یا anything, but why is ur brother in intensive care. (If آپ don't want to say آپ don't have to, آپ could always باکس ان me otherwise if آپ don't want everyone to see. Anyway if آپ 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 آپ 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)

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