I just found out about this problem that can affect pet bird owners.
My birds don't appear sick, but I have irritation in my upper respiratory system for quite a long time. I was thinking it's just a cold season regular cold, plus my immune system isn't in the best shape.
If anyone has info on this problem, please share.

It's also called psittacosis, and you might find more information about it if you google for it using that name. Here's a link to start things off: https://en.wikipedia.org/wiki/Psittacosis

That really sucks. If my parents find out about this, bye coco, kiwi, pip and satchimo. Is it common? Can you easily get it?

Back when you were asking your parents to let you keep the birds in your room, you said your father pulled up a list of diseases that could be spread by birds. Psittacosis would definitely have been on the list so he's heard about it already, and you were able to keep the birds anyway. Your birds can't get it unless they have fairly close contact with an infected bird, so you're pretty safe.

thanks,
my questions are:
1) is it possible that birds have it but show no visible symptoms
2) is it possible that human contracted it but has no idea he/she is sick? I mean, is it always acute disease with symptoms that someone can't ignore?

Concern came from my mom today after she heard "something"/ I have never heard about it until today.

The disease actually tends to be worse for humans than for birds, but even in humans the symptoms can be fairly mild sometimes. It's really more likely that you have bronchitis or something like that, but if you see a doctor they can run tests and find out what's going on. Birds don't always show symptoms.

thanks Carolyn.
With me being busy and having 10 birds, it's not very clean here (I m trying but honestly can't say I am managing to have it the way it should be). Any health hazards because of this? Are birds in any danger? people?

Cockatiels create a lot of dust so it's best to use an air purifier when you have a lot of them. It helps prevent you from getting bird keeper's lung. https://en.wikipedia.org/wiki/Bird_fancier's_lung Otherwise it's not really a problem, as long as you don't have mold growing in the bottom of the cage or something like that.

I am also always sick in my lungs (I cough all the time and sometimes I really feel "something", I don't want what) and my immune system isn't the best either. I had actually found out about this disease last year, but never had any test taken...

can't say I feel relieved LOL