Everyone has posted what I would have told you about a diagnosis at this age means he is pretty healthy, exercise and activity is VERY important and if your son can stand running and other active sports- it is very important to encourage it.
Just a breif history on my relationship with CF... I am married to a 24 year old man with CF, who will be 25 in October. He was diagnosed at 18 months with failure to thrive (no weight gain, less than 25% for his age...) and lung infections. After his diagnos and appropriate medications and therapy, he gained weight and has been fairly healthy since then. In 2003 he started having more frequent lung infections (he previously had 2-3 from the time of his diagnosis until he was about 22, so they treated him with a new medication which seemed to make a difference. We also got a chest PT (airway clearance) vest from www.thevest.com. It realy cuts down on the time I spend doing manual chest clearance on him (use to be 1 hour in the morning, 1 hour in the evening) but now he uses the vest 2 times a day for 20 minutes and I don't even have to be home for him to do it. I would attribut his high health to his activities (he played soccer all throughout elementary, JR high and high school), medications (although as a teen he went through a 2-3 year rebellious "im not doing my meds" phase) and his WEIGHT. Maintaining his weight has been very important to him and I believe is directly related to his health as well. He eats all the time, even with the enzymes, drinks boost plus nutritional shakes (calories and protein are important, as is fat but if you take in enough calories/protein the fat will take care of it's self) and drinks weight gainer shakes. He is currently 192lbs and 6 feet tall, quite a feat for someone with CF. Also, in the last few years he has spend less time doing fat burning activities (i.e. running, soccer) and more time doing weight lifting to put on muscle (which weighs more) and therefore keep his weight at a healthy level.
Mark is a full time student and will graduate with his BA in May 2006 where he plans to work full time if his health can handle it, but at least part time.
We are planning for a family for a few years and are both very excited about having children. This is not a fact for every male with CF, but some males with CF are infertile. This does not mean they cannot have biological children, there are methods to extract sperm from the testicles. The "infertility" part just means they might not be able to get a woman pregnant naturally. I have actually created a CF website geared towards males who have CF and have male factor infertility. You can visit it at www.cysticfibrosismaleinfertility.com if you are interested. I am sure it is not at all a priority right now, but someone is sure to tell you that male infertilty may someday have a part in your sons life, and then leave you with no explanation. Many doctors do that to teen and young adult males and then leave them without any information about what they can do about it so when it comes time... you'll have the appropriate information.
I wish you the best and encourage you to utilize this site for support and just some friends who are going through or who have gone through what you are experienceing. As a wife to someone with CF, I can't always relate to everything a parent is posting as I am a wife, not a mother of a CFer. But all the same, there are different questions that I cna answer about an older CFer that a parent with a young CFer hasn't experienced yet.
Welcome to the site,