Cough is the sudden, repeated contraction of the diaphragm and other respiratory muscles, often producing a distinctive sound. A cough is often a reflexive response to abrasions or irritations in the throat, lungs and bronchi. It is the body’s way of getting rid of mucus, phlegm and other gunk that has accumulated in the lungs. It can be caused by a cold or flu, allergies or even stress. Coughing is a natural reflex that occurs when your body detects something irritating or harmful in the air — like pollen or dust particles — and wants to expel it.

Persistent coughing can be annoying, especially when it wakes you up at night. If you have no other symptoms besides a cough, it’s best to wait it out and see if it goes away on its own. But if your cough doesn’t go away within two weeks, or if it gets worse after two weeks, talk to your doctor about it.

An effective cough helps clear secretions and irritants from the airways and lungs, while an ineffective or excessive cough may be a sign of an underlying condition.