I am nearly 15 years old, and i think i may have a mild case of cystic fibrosis because i have a few of the symptoms, but is it possible because of my age?X
Cystic Fibrosis symptoms can occur at any age, if you have a family history of CF (especially if your parents or grandparents have it) then there is a chance you could be suffering too.
There are a number of respiratory conditions that can cause similar symptoms to CF though so don't jump to conclusions straight away.
At 15 people do commonly suffer from very slight shortness of breath and chest pains, but if you are coughing persistently/coughing up mucus or blood you need to see your GP as soon as possible to be diagnosed.
Depending on what part of the gene is affected you can get a milder form of the disease that's doesn't show all the symptoms of the most common form but you really need to discuss this with a doctor, especially if there is a history of it in your family 
Well pretty much anything is possible, but to me it seems unlikely because for a long time now infants are screened at birth for cystic fibrosis, but if you are concerned contact your doctor and ask him/her what they think, and if they believe that it could be possible, you need to testing done.
my freind has it and they found out when she was like 3ish so im not sure about 15.. then again she has a pretty severe case.