Bronchodilation is the dilation of the airways in the lungs due to the relaxation of surrounding smooth muscle. It is the opposite of bronchoconstriction.

What is the effect of bronchodilation?

Bronchodilators are a type of medication that make breathing easier by relaxing the muscles in the lungs and widening the airways (bronchi). They're often used to treat long-term conditions where the airways may become narrow and inflamed, such as: asthma, a common lung condition caused by inflammation of the airways.

When does bronchodilation occur?

Smooth muscle contraction leads to bronchoconstriction (decrease in the diameter of the bronchioles) while smooth muscle relaxation leads to bronchodilation (increase in the diameter of the bronchioles). Parasympathetic stimulation causes bronchoconstriction while sympathetic stimulation causes bronchodilation.