Bronchodilator action is the ability of certain substances or drugs to dilate the bronchi, making breathing easier. Bronchodilators are used to relieve bronchial smooth muscle spasms that occur in respiratory diseases such as bronchial asthma, chronic obstructive pulmonary disease (COPD) and other conditions accompanied by difficulty breathing.

Bronchodilators work by relaxing the muscles of the bronchial walls, which leads to their expansion and improved air permeability. This makes it easier to breathe, reduce shortness of breath and improve tissue oxygenation. Bronchodilators can be short-acting or long-acting depending on the duration of their effects on the body.

Bronchodilators include drugs of such groups as beta-adrenomimetics (salbutamol), anticholinergics (ipratropium) and methylxanthines (theophylline). They can be used as inhalers, tablets, or inhalation solutions. Bronchodilators help to quickly relieve bronchial spasm and facilitate breathing, but they should be used as prescribed by a doctor, as improper use can cause side effects.