Expert Voice:

What’s causing that lingering cough?

Got a persistent cough you just can’t seem to get rid of? It may be more than a remnant of that cold you fought off a few weeks ago. If the cough has lasted more than eight weeks or longer in adults, and four weeks in children, it’s considered “chronic”.

What causes chronic cough?

According to respiratory physician DR JIM TEO YEOW KWAN, there are a number of causes, and the treatment options vary accordingly.

Infections

“A cough can linger long after other symptoms of pneumonia, flu, cold or other infections of the upper respiratory tract have gone away,” he says. “A common but under-recognised cause of chronic cough in adults is pertussis, also known as whooping cough.”

If fever persists and purulent phlegm persists for more than five days, it’s likely a bacterial infection that’s causing your chronic cough, and antibiotics may be prescribed.

Chronic bronchitis

Chronic cough can also be a sign of chronic bronchitis, a long-term respiratory tract infection that most commonly affects current or former smokers.

“This long-standing inflammation of the major airways can cause a cough that brings up coloured sputum,” says Dr Jim Teo. “Chronic bronchitis is usually part of the spectrum of smoking-related lung disease called chronic obstructive pulmonary disease ( COPD), which includes emphysema as well. Chronic bronchitis and emphysema often coexist in current or former smokers with COPD.”

Postnasal drip

“When your nose or sinuses produce extra mucus, it can drip down the back of your throat and trigger your cough reflex. This condition is also called upper airway cough syndrome (UACS).”

Luckily, antihistamines and decongestants are among the different types of drugs that can be used to treat allergies and postnasal drip.

Asthma

“An asthma-related cough may come and go with the seasons, appear after an upper respiratory tract infection or become worse when you’re exposed to cold or certain chemicals or fragrances,” says Dr Jim Teo. “And, in one type of asthma, coughing is the main symptom.”

The most effective treatments for asthma-related cough are inhaled asthma drugs, which reduce inflammation and open up the airways.

Reflux

“Gastroesophageal reflux disease (GERD) is a common condition where stomach acid flows back into the oesophagus, creating constant irritation that can lead to chronic coughing,” explains Dr Jim Teo. “This coughing, in turn, worsens GERD, creating a vicious cycle.” He adds that when lifestyle changes don’t take care of the acid reflux, a patient may be treated with acid blockers, medications that block acid production.

Blood pressure drugs

According to Dr Jim Teo, angiotensinconverting enzyme ( ACE) inhibitors, which are commonly prescribed for high blood pressure and heart failure, are known to cause chronic cough in some people.

When to see a doctor

See your doctor if your cough has lasted for weeks, you’re coughing up blood or if your cough is associated with fever, shortness of breath and chest pain. It’s also important to see a doctor if your cough is causing you serious problems such as keeping you from sleeping or interfering with your work or everyday activities.

Cough suppressants may be prescribed, particularly if the reason for your cough can’t be determined right away. However, Dr Jim Teo says there’s no evidence that over-the-counter cough medicines are effective in treating chronic cough.

The Respiratory Practice has five locations: Gleneagles Medical Centre, Mount Elizabeth Medical Centre, Parkway East Medical Centre (Joo Chiat), Farrer Park Medical Centre and Mount Alvernia Medical Centre D. respiratorypractice.com