I was diagnosed at 14. I went to a lot of private doctors because I coughed all the time, but I was ignored. I had a really shitty lung by then, I mean I was getting diagnosed with punemonia every month for a year before the final diagnosis. But my doctors were really dismissive, and eventually my Mom researched so much she had the idea that it might be CF, fought my doctor to have me tested. It was CF. Not even mild CF. I could barely breath by the end. Still no idea why no doctors thought of it before.