bronchospasm

narrowing of bronchi by muscular contraction in response to some stimulus, as in ASTHMA and BRONCHITIS . The patient can usually inhale air into the lungs, but exhalation may require visible muscular effort and is accompanied by expiratory noises that are clearly audible (see WHEEZE ) or detectable with a stethoscope. The condition in which bronchospasm can usually be relieved by bronchodilator drugs is known as reversible obstructive airways disease and includes asthma; that in which bronchodilator drugs usually have no effect is irreversible obstructive airways disease and includes chronic bronchitis.