What is the function of an expectorant?

An expectorant is a type of medication that helps to make coughs more productive. This means it aids in the clearance of mucus or phlegm from the respiratory tract. When a person is suffering from conditions such as bronchitis or a cold, mucus can build up, making it difficult to breathe and creating a non-productive (dry) cough. Expectorants work by thinning the mucus, which makes it easier to expel through coughing. This not only helps to clear the airways but also enhances breathing comfort and can alleviate congestion.

The other options do not describe the role of an expectorant. Suppressing coughing is the role of antitussives, while relieving headaches is typically associated with analgesics. Increasing immunity does not fall under the functioning of expectorants but rather involves immunomodulators or vaccines.