In a previous incarnation I worked as an Administrator in the RAF. The RAF takes a very dim view of pilots with hay fever (or it did). Therefore none of the RAF fast jet pilots I knew had hay fever. A huge number of them got 'summer colds' which mysteriously cleared up (temporarily) with anti-hystemines (spelling?), but none of them had hay fever. You'd see them in July wandering around with their eyes streaming, sniffing and bunged up noses from their 'summer colds', near medical time, a few anti-hystewotsits an hour before and a cold face wash and they felt fine. Funny that.
Also it is not unusual to hear that you get a bad turn and breathless 'at night'. I would hazard a guess that you get wheezing, and breathlessnes at about 3 am. This is associated with the time that dew forms (I jest not) and can lead a large number of people to get 'asthmatic tendencies' as the doc's call it and they give you Ventolin, which makes it better. It's primarily associated with damp (especially if your home is old) and dust mites. How old is your house? do you have fitted carpets (dust mites hide in the edges where you cannot vacumn them up), remember in the good old days you'd see the women battering rugs with beaters over a line, huge clouds of dust etc. Well funny thing kids didn't get much asthma then, floors were wooden, and no-one had fitted carpets. They had rugs which they beat regularly. When did you last lift your fitted carpets, take them outside and beat them........... same as me probably. If your house is not brand new, then you'll have wheel-barrow loads of nasties living in the edge of your carpets. They love you and your families lungs.
My Brother used to suffer from asthma badly. He lifted his carpets, sanded down the wooden floor boards and vernished them. House looks great now. No more asthma.....strange. Of course this might not relate to you at all, but its a bit of a thing with me.