Thanks, lj, for all the info.
If I have time I may go through some previous comments and post links to ones useful for respiratory illness, like cough syrup recipe etc.
Reminds me I need to make dragon balm and soothing balm, not sure if I posted recipes. Dragon is the natural version of tiger balm, for headaches, muscle and joint pain, and helps a lot with breathing by rubbing on chest, sinus areas on face, and I put in my nostrils. Much better than tiger balm. It is strong!