Smoking prevents healing of the inflamed air passages and results in continuing troubles. Persistent coughing is often present in chronic diseases of the lung such as asthma, emphysema and cigarette smokers bronchitis. Persons with these ailments most often have experienced difficulties for many years and understand the nature of the cough. Asthma sometimes presents as a nagging cough, with little wheezing or breathlessness being noticed by the patient. And asthma can have its start at any age.
Lung cancer is the most feared cause of a persisting cough.
For those who smoke, this fear is justified. For those who do not smoke, lung cancer is very seldom the cause of the symptom. Pain, weight loss, and the presence of blood in the expectorated sputum are associated troubles that make a diagnosis of lung cancer more likely. Chronic sinusitis is one of the most common causes of a nagging cough in the elderly. Secretions produced by the inflamed sinus membranes drain down the back of the throat and enter the passage to the lungs.