Health Tips › Chronic Cough

When a cough just doesn’t go away

Cough is a common condition that everyone has experienced at one time or another. But if it develops into a chronic cough, you could be looking at something far more serious. Respiratory Physician Dr Jane Yap explains why.

A physically active 52-year-old lady presented what seemed like a normal cold. She was treated for her cold. Yet the cough and congestion in the nose and chest persisted. Feeling that something was not right that a cold lasted so long, the family doctor referred the lady to chest specialist Dr Jane Yap.

A chest x-ray was done and showed a huge right lung tumour. Further investigations confirmed lung cancer in the last stage. This was just 8 weeks after she first sought medical attention from her family doctor.

This true story reveals how a simple chronic cough can have far more sinister implications than most people imagine. At Dr Yap’s clinic, as many as one third of the cases she sees are cough-related. She takes us through the different types of cough and their causes.

Q: Why do we cough?
Cough is an important mechanism that allows us to clear the airway of secretion and foreign material. However this is also a means of spreading infection. Chronic cough is troublesome and may have complications like insomnia, muscle pain and rib fracture.

Q: When does a cough become chronic?
In general, a cough becomes chronic when it lasts longer than 3 weeks. By then, the patient is likely to have consulted a number of family doctors and eventually ended up seeing a specialist.

Q: What are the common causes of cough?
Acute cough is most frequently due to the common cold, followed by bacterial infection of the sinus, allergic rhinitis, asthma and chronic obstructive pulmonary disease (COPD) exacerbation. Although less common, it can also be associated with serious conditions like pneumonia and heart failure.

Chronic cough can result from a single cause or a combination of two or more conditions. The most common causes among the non-smokers are post-nasal drip syndrome (PNDS), asthma and gastroesophageal reflux disease (GERD).

A person with PNDS usually has a feeling of something dripping down his throat. He tends to experience a need to clear the throat, nasal congestion, discharge or hoarseness. Usually, he would have had a recent cold or suffer from allergic rhinitis, acute or chronic sinusitis.

Asthma must be considered in all patients with a chronic cough even though there is no other characteristic complaint of asthma. This condition is called cough variant asthma. The treatment is the same for asthma presenting with shortness of breath and wheezing.

GERD is caused when contents from the stomach flow back (reflux) into the gullet. It is not easy to diagnose as more than half of the persons with cough due to GERD are unaware of reflux. They may not have the typical symptoms like heartburn, sour taste or regurgitation. GERD may have a self-perpetuating cycle in conjunction with another cause of cough.

Q: Is a cough always infectious?

Strictly speaking, a cough is not infectious unless it is caused by an infection from a virus, bacteria or tuberculosis.

Q: The colour of phlegm varies from clear to yellow, what do they indicate?

In general when it is thick and green or yellow, it implies infection. When it turns clear, it means the infection is resolving and responding to treatment.

If the phlegm is clear, it is more like hypersensitivity as in asthma or rhinitis, or drug and GERD induced cough.

When there is blood in the phlegm, it could indicate bleeding along the mucosal lining from the pressure of coughing. Or it could be indicative of a more serious infection like TB, bronchiectasis or cancer. Further investigations would be required to obtain a proper diagnosis.

Q: Is its good to suppress a cough?

It depends on the cause, If it is due to an infection, it is best to get the phlegm out and not block up the airway.

Q: What are other causes of chronic cough?

Lung Cancer should be considered a potential cause in all especially in present or prior smokers. Tobacco smoking causes the great majority of lung cancer. Cough as a presenting complaint may be ignored as smokers are expected to cough. Other symptoms include bloody sputum, loss of weight, hoarseness, shortness of breath and lumps in the neck. These will usually bring them to medical attention earlier.

Tuberculosis of the lung has not left us. It can present itself with cough, bloody sputum, loss of weight and fever. There may be a history of close contact with a TB case. The other risk factors for contracting TB are underlying Diabetes, cancer and decreased immunity as in HIV infection.

Drug-induced cough is a possibility in persons with hypertension and taking certain blood pressure lowering medicine. The cough is usually dry and hacking. The cough is usually resolved within a month when one stops the medication.

Pertussis, or whooping cough, is an upper respiratory infection, sometimes called the 100 day cough. A deep "whooping" sound is often heard when the patient tries to take a breath and the coughing can make it hard to breathe. Antibiotics are the prescribed treatment.

Habitual and Psychogenic Cough can only be diagnosed after other illnesses have been ruled out. Suggestion therapy, psychological counseling or psychiatric intervention is appropriate.

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Dealing with Cough – some useful tips

• Stop smoking. Tobacco smoke causes inflammation of the airway, excessive mucus secretion and impairment of normal clearance of mucus. It can cause lung cancer and COPD.
  
  Smokers frequently have a chronic cough from chronic bronchitis. Often they do not seek medical attention because they expect to cough as a result of smoking.
  
  
• Cover your mouth if you have to cough, keep your hands clean and avoid crowded places. Coughing spreads infection, so be civic-minded and do your part to prevent the spread.

• Complete the prescribed course of antibiotics. Be disciplined and follow doctor’s orders. You will not get well and worse if you have been irregular with the medication, the bacteria could turn resistant to the antibiotics.
  
  
• Seek medical attention early. If your cough is chronic or associated with shortness of breath, with or without wheezing. Other warning signs are blood in the sputum, high fever or persistent fever, and loss of weight.

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Dr Jane Yap is a Respiratory Physician based at Mount Alvernia Medical Centre (Blk A, #B1-4). Tel: (+65) 63569928.