Chronic Cough

Chronic cough is a common condition in ENT. It typically starts after an upper respiratory tract infection (URTI) several weeks or months ago, and despite being on cough medication, the cough remains.

While it is common to have acute cough associated with URTI, chronic cough – a cough that lasts for more than 8 weeks – can be frustrating, embarrassing and painful.

About 40% of the population will experience chronic cough at some point in their lives.

A cough reflex is initiated by the stimulation of sensory nerves in our pharynx (throat), larynx (voicebox) and lower respiratory tract, and sends signals to the brain.

Cough can easily be triggered by exposure to cold, dry air, noxious stimulants or even by continuous talking.

1. During an upper respiratory tract infection, the nerve receptors located throughout the respiratory tract become hypersensitized
2. Common pre-existing conditions like post-nasal drip, gastroesophageal reflux disease (GERD) which were previously not severe enough to initiate a cough, can now perpetuate it.

1. Post-Nasal Drip
   1. The nose helps warm, filter and moisten the air we inhale through the production of mucus every day to line and protect the respiratory lining
   2. Any condition that increases the normal production of mucus may lead to the mucus flowing down the back of the nose into the throat
   3. Conditions: allergic rhinitis, sinusitis etc.
2. Gastroesophageal Reflux Disease (GERD)
   1. Up to 40% of patients with chronic cough have GERD
   2. The acid contents in the stomach flow backwards (reflux) up into the throat and irritate the larynx
   3. Phlegm is produced to neutralize and protect the larynx but this also leads to troublesome and painful throat clearing
3. Swallowing Disorders
   1. As we age, several changes in our digestive tract predispose us to developing swallowing difficulties
   2. E.g. microscopic strokes in the brain which affect swallowing coordination
4. Paradoxical Vocal Cord Movement (PVCM)
   1. Estimated that 56% of patients with chronic cough have PVCM
   2. Occurs when the vocal cords come together during breathing, instead of opening and allowing air into trachea (windpipe)

1. Steam inhalation
   1. 10 minutes, 2-3 times a day will soothe the throat
2. Frequent sips of warm water
   1. Help suppress the urge to cough
3. Sleep with the head of the bed elevated
   1. Reduces GERD
4. Avoid eating 3 hours before bedtime
   1. Reduces GERD
5. Avoid any food that triggers cough
   1. E.g. citrus fruits, spicy, fried and oily food frequently worsens the cough

Depending on what underlying medical condition you have, your ENT doctor will prescribe specific medication for that condition, in order to alleviate the coughing.