Question: What is the proper etiquette while sitting zazen and I have a head cold? Should I get up and leave to blow my nose or cough?

Answer: Just sit through the discomfort. Here are some words of instruction that I found on the web site ordinarymind.com that seem to address this issue very well:

"Be silent and sit as still as possible in the zendo. Once the sitting has begun, do not adjust your sitting posture or move in any way. That means no scratching of itches, nose blowing etc. Ordinarily we try to avoid many varieties of discomfort; in the zendo we practice sitting still in the midst of our experience, attending to the forms it takes as well as to our reactions and resistances to experiencing it."