Cough is a natural defence mechanism of the respiratory tract. It can be a warning sign for many respiratory as well as non respiratory diseases.
Acute cough which occurs in association with upper respiratory tract infection is usually self limiting and will resolve within 3 weeks.
Chronic cough which is cough that persists for more than eight weeks in adults, and four weeks in children can lead to exhaustion,
sleep disturbance, cough syncope, urinary stress incontinence, hernia, and rib fractures.
Cough can be either be of two types, dry or productive cough. Most common causes for chronic cough include tobacco smoking, post nasal drip,
viral infections of the upper respiratory tract, gastroesophageal reflux disease (GERD), cough variant asthma, eosinophilic bronchitis, post infectious,
side effect of either oral hypoglycemic agents, or antihypertensive medications and tuberculosis.
Post nasal drip is the accumulation of mucus in the throat; symptoms can be the conscious feeling of thick secretion at the back of the throat, frequent throat clearing or nasal discharge. Gastroesophageal reflux disease is a non-respiratory cause of chronic cough. It is an acid reflux disease, and cough is a result of the reflux, symptoms associated with cough may include heartburn, and acid regurgitation.Eosinophilic bronchitis and asthma are airway inflammation diseases due to allergic irritation of the airways.
Chronic cough requires medical attention as the complications lead to considerable morbidity. For adequate treatment, a detailed clinical history including any previous respiratory diseases, drug history, travel history and occupational history along with investigations are required. Basic investigations that are needed include x-rays (Chest and Paranasal Sinus), allergy testing, and pulmonary function tests. Further investigations can be warranted depending on the differential diagnosis.
Simple lifestyle modifications can reduce the frequency of cough, such as avoiding exposure of allergens and irritants, protective masks to avoid pollution and basic hygiene.
Article by Dr Anantha Subramanian, MD
Specialist Pulmonology and Sleep Medicine