Chronic cough is characterized by cough lasting more than 8 consecutive weeks. Chronic cough is a tormenting symptom that often leads to a severe decrease in a person's quality of life. The effects of chronic cough can range from the social isolation of the patient to urinary incontinence and hernia from excessive coughing. The overwhelming majority of patients with chronic cough can be helped with proper diagnosis and appropriate treatment.

CAUSES

External irritating factors
The most common cause of chronic cough is cigarette smoke, environmental pollution, dry air, various allergens, and dust or inhaled chemicals.

Intrathoracic causes
The most common pulmonary causes of coughing are asthma, emphysema and chronic bronchitis. Less common causes are lung cancer, swollen lymph nodes, pleural effusions (lung fluid), interstitial lung diseases, heart failure, pericarditis, and infections such as pertussis (whooping cough) and tuberculosis of the lungs.

Causes from the Higher Respiratory System
Chronic sinusitis and postnasal dripping, otitis (external ear infection), or pharyngeal infections are often causes of chronic cough.

Gastro-oesophageal reflux disease (GER)
A common cause of cough is often underestimated. Gastric fluid regurgitation caused by loosening of the gastroesophageal sphincter causes coughing between other symptoms such as heat burn and acidic burping.

Other causes
• Some drugs have a side effects with chronic cough, most commonly with angiotensin converting enzyme inhibitors used in arterial hypertension 
• Psychogenic cough which is a dry cough. 
•  Foreign body.

DIAGNOSTIC APPROACH
Patients with chronic cough should be examined after a detailed medical history, chest X-ray, occipito-mental X-ray and spirometry. 
However, if the cause of cough is not visible, the examination will extends to chest CT and to bronchoscopy. 
Psychogenic cough is a diagnosis of exclusion.