I have very thick mucus from my lungs, nose, and even vagina (>1yr) is it possible to have cystic fibrosis and not be diagnosed until adulthood?

Possible: If you have significant concerns about persistent lung congestion and excessive mucus production, frequent sinus infections, consult a pulmonologist for testing and advice. Mild or atypical cases of cystic fibrosis may not be diagnosed until adulthood.

Yes, rarely.: Most cystic fibrosis pts are diagnosed in childhood, but some patients with milder forms of the disease don't get diagnosed until early adulthood. Usually respiratory complaints or COPD (a type of chronic lung disease) in nonsmokers are the "triggers" that lead to testing. A sweat chloride or sodium test will usually make the diagnosis (confirmed by CFTR gene analysis). TTYD or use HealthTap Prime

Mild form possible: It is possible that a mild form of cystic fibrosis may not be detected till adulthood. The test is a relatively simple sweat test. Wish you good health.