Some people have posited that coughing is seasonal; that it is more rampant with the coming of certain crops. This (Nigerian) school of medical thought may be right as more cases of coughing are being reported and treated by health personnel these days in both private and public health facilities. You probably have a case in your home or office. In most cases, when one member of the family starts coughing, it may spread if not treated at once. And when treating, please, treat everyone.
Coughing is a reflex action started by stimulation of sensory nerves in the lining of the respiratory passages, that is, the tubes which we use to breathe.
When a person coughs, there is a short intake of breath and the larynx (the voice box) closes momentarily. The abdominal and chest muscles used for breathing contract, which in turn increases the pressure needed to drive air out the lungs when the larynx re-opens.
The resulting blast of air comes out at high speed, scrubbing and clearing the airway of dust, dirt or excessive secretions. Coughing is a common symptom when the airways are ‘tight’, as in asthma.
The cough reflex is a vital part of the body’s defence mechanisms. Normally, the lungs and the lower respiratory passages are sterile. If dust or dirt get into the lungs, they could become a breeding ground for bacteria and cause pneumonia or infection in the breathing tubes.
What causes coughing?
Coughing usually means there is something in the respiratory passages that should not be there. This can be caused by breathing in dust particles in the air or when a piece of food goes down the wrong way.
It could also be a sign that an infection in the lungs is making the respiratory passages produce phlegm.
Coughing can be provoked by:
• The common cold, which is a frequent cause of acute cough that usually settles in less than three weeks.
• Sucking material into the breathing tubes from your mouth.
• More severe illnesses, such as pneumonia, acute heart failure or pulmonary embolism (a clot in the blood vessels of the lung).
• Smoking, which often causes chronic cough (smoker’s lung).
• Asthma – particularly in children who may only cough and show no wheezing.
• Stomach acid coming back up the gullet and spilling over into the windpipe (gastro-oesophageal reflux).
• Medicines used in heart disease called ACE inhibitors.
• bacterial or viral infections in the lungs, e.g. acute bronchitis, pneumonia, whooping cough, croup in children
• rarely coughing can be provoked by psychological illness
• Damage to the nerves that supply the vocal chords (known as vocal chordpalsy) and chronic cough can occur.
Coughing is more efficient when preceded by a full intake of air.
For this reason, patients with weak muscles, poor coordination of airway closure and re-opening, or who have airflow obstruction will have a poor cough and be susceptible to complications including infection in the lower respiratory tract and pneumonia.
How can coughing be treated?
Coughing is a symptom, not a disease. It is the underlying cause of the cough that needs to be treated.
You should consult your doctor if any of the following symptoms accompany a cough, so that possible underlying causes can be investigated and treated where necessary:
• coughing up phlegm that is green, rusty brown, yellow, blood-stained or foul smelling
• chest pain
• shortness of breath or wheezing
• pain and swelling in the calf
• recurrent night-time cough
• whooping cough or croup
• worsening smoker’s cough
• sudden weight loss
• fever and sweating
• hoarseness of the voice with a chronic cough that doesn’t clear up spontaneously.
If you can’t cough but need to, problems soon arise. Equally, when coughing is painful (for example, because of a broken rib), patients try not to cough and this can be dangerous.
Ineffective clearance of the airway can lead to a chest infection and possible pneumonia. In these circumstances, pain-relieving medicine can be useful to permit an efficient cough.
Infections in the breathing tubes can be caused by both bacteria and viruses, although the most common cause in children is a virus. Bacterial infections can be treated with antibiotics, but viral infections cannot.
Vaccination has greatly diminished the incidence of whooping cough (pertussis), but if this is the diagnosis, antibiotic treatment with a macrolide antibiotic such as erythromycin decreases the severity of this illness within the first week of treatment.
Asthma may cause coughing without wheeziness. This tends to be worst through the night, disturbing sleep. It may be the first sign of asthma in children, or a warning sign that asthma is worsening or not controlled properly. Conventional asthma treatment with inhaled anti-inflammatory preventative medicines and relievers will usually relieve a cough that is due to asthma.
However, a metered-dose inhaler may itself induce cough, and you may need to use a large volume spacer device or a dry powder inhaler instead.
Giving up cigarettes will lessen or abolish smokers’ cough in 94 per cent of people within four weeks.
How effective are the cough medicines?
In cases where a cough is particularly annoying, but not life-threatening, a simple cough mixture may be useful. There are a range of over-the-counter medicines that can be helpful in such circumstances.
Taking these can be justified when there is no special reason to suspect any serious underlying disease, such as the symptoms listed above. You should ask your care giver for advice on which of the many available over-the-counter cough remedies are suitable for you.
A productive, chesty cough, in which phlegm is coughed up, should be treated with an expectorant cough mixture to help loosen the phlegm and make it easier to cough up from the airways. Expectorants contain ingredients such as guaifenesin, ipecachuana or ammonium citrate.
A non-productive, dry, tickly or irritating cough, in which no phlegm is coughed up can, be treated with a cough suppressant to reduce the cough reflex. Cough suppressants include pholcodine, dextromethorphan and codeine. Other cough suppressants include simple linctus, glycerine and lemon and honey, which coat and soothe the back of the throat.
Antihistamines such as diphenhydramine and promethazine reduce the cough reflex and also dry up nasal secretions, which can be useful for coughs that are caused by a postnasal drip (mucus running down the back of the throat), or are associated with a cold.
Ipratropium bromide nasal spray also reduces watery nasal secretions that can cause postnasal drip and contribute to a cough.
Some cough remedies also contain sympathomimetics such as ephedrine, for their airway relaxing and decongestant effects, and can be useful if you have a blocked nose as well as a cough.
Patients should not treat themselves with cough mixture for any longer than two weeks. If the cough persists, a visit to the doctor is definitely required – informed medical assessment will help identify the underlying cause and allow treatment.