Bronchospasm or a bronchial spasm is a sudden tightening of the muscles in the walls of the bronchioles. It is caused by the release (degranulation) of substances from mast cells or basophils because of anaphylatoxins. It causes difficulty in breathing which can be very mild to severe. Bronchospasms can be caused by asthma, chronic bronchitis and anaphylaxis.
Bronchospasms are a serious potential complication of placing a breathing tube during general anesthesia. Some of the things that can cause bronchospasms are: consuming foods, taking medicines, allergic responses to insects, and hormone levels, particularly in women.