I Have a dust mite allergy since 4 years.Earlier i didn't noticed anythng which is happening now a days.From 3 months i am experiencing tightness in my upper chest and a liitle at tha back ,it may be due to acidity.Most concerning for me is that there is a little blood from my sputum and rarely from my cough .It usually happens when i woke up from power naps at noon.The amount of blood is low in most cases and it may be 1 tablespoon at heightest.It is alarming or normal for me ??