Hey,
Don't worry if it's just streaks in your sputum.
I have a system; maybe it'll help:
Green Alert: No blood. Regular routine.
Yellow Alert: A bit of streaking in your sputum. Don't worry, but pay more attention than usual to how your lungs are feeling, like if they're more infected, more inflammed, too dry etc.
Orange Alert: More blood than sputum, but not coming out on its own or anything. Here I try not to do too much activity or anything that will aggravate it too much, but I still do physio and take my meds.
Red Alert: Frank blood. The real deal, full on bleed. Coming out on its own even without you coughing (just exhaling brings it up).
Step 1) DON'T PANIC. You will probably freak. Don't worry. You're not going to bleed to death. You're going to be ok. Try to remain as calm as you can because getting excited only makes it worse.
Step 2) Sit down somewhere, gently...gently.
Step 3) Get somebody to bring you several glasses of ice water and an ice pack or a bag of peas. Take little sips of the water and put the ice on your chest. You're trying to constrict the blood vessels here. Try not to cough too much and just breathe as normally as you can.
Step 4) Wait it out, drinking the water. Check your sputum in half an hour. If it looks like it's darker, that probably means it's clotting up in there. Wait several hours and then do physio, but gently.
If it's not stopping, phone your CF doc and explain what's going on. If it's lots and lots of blood, you'll probably have to go in for an embolization, which is a procedure where they inject little balls into your bloodstream to block off the hole. It doesn't hurt, and you'll be fine. They'll probably put you on antibiotics to cover any infection this might have caused.
If it stops on its own, clear it out but don't do any heavy physical activity for 24 hours. Call your doc and monitor your temperature. Sometimes these bleeds can cause infections, so just watch it.
Don't worry. This is normal for us. It's just part of CF, and maybe you'll never get used to it (I still haven't!) but at some point you'll know what to do and be less afraid.
Happy Bleeding!
Love
Hermit