Cough is seen in many medical conditions. In order to correctly differentiate between them, it is important to accurately note the duration, type and characteristics of the cough, as well as any other accompanying symptoms.

This information will be very helpful to the attending physician in determining the cause of the cough and the most appropriate cough treatment. The cough may persist for a very short time and may be a solitary symptom. The cough may also persist until the cause is identified and treated. How serious the cough is depends on the disease causing it.

Although a temporary cough is usually normal, a persistent cough that does not go away is not. A persistent cough or other symptoms such as shortness of breath, sputum production or bloody sputum may indicate a more serious medical problem.

There are classifications according to the duration and types of cough. To determine the cause of the cough, it is important to identify which class it belongs to. Acute cough of one of these types and classes starts suddenly and lasts up to 3 weeks.

A chronic cough lasts for more than 4 weeks. In between, sub-acute cough persists for 2 to 4 weeks. A nocturnal cough is used to describe a cough that only starts at night.