I heard there were mild cases of cystic fibrosis, and I am wondering if it is possible that I have it. I am 17 and I have always been spitting up excessive mucus. I've just started worrying about it because I think it's getting worse. I'm skinny and i have digestive problems but never went to a doctor about it. could it be that I just have a weak system or something? I don't have a huge respiratory problem and it has never been so bad that I had to stop and get help. My mom also has the yucky mucus, so I know I got it from her. Any info would be much appreciated!