What normally triggers them? DS is 10 and has never had a nosebleed in his life, but in the last couple of months (I'd say since about April) he's had about 6. Always when he wakes up in the morning, some are worse than others but I can't work out what triggers them to try and avoid it. He does complain of headaches sometimes, although he's a fairly anxious child and doesn't particularly like school so at the risk of sounding harsh, I never know whether he's being honest or saying he has a headache to try and get out of school.
The pollen count was pretty high here yesterday, so could that perhaps be a factor?