The universal trigger for fear is the threat of harm, real or imagined. This threat can be for our physical, emotional or psychological well-being. While there are certain things that trigger fear in most of us, we can learn to become afraid of nearly anything.
“Respiratory” could be a result of inhalation
Cholesterol (especially LDL*) tend to get into macrophages which migrate into blood vessels. Macrophages with cholesterol cannot get out of the vessels and stay there which causes a lipid mass in arteries. That causes atherosclerosis.
Puberty, menopause, substance abuse, disease and pregnancy are the biggest ones.