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. The resulting inflammation of the bronchial tubes leads to the typical irritative cough. The cough is usually dry, but secretions may be brought up after awakening in the morning. It abates only after successful treatment of the sinus condition. Regurgitation of stomach fluids during sleep occasionally is the source of a persisting cough.