Coughing

Reviewed by Dr John Pillinger, GP



Coughing is a reflex action started by stimulation of sensory nerves in the lining of the respiratory passages - the tubes 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 angiotensin converting enzyme (ACE) inhibitors.

bacterial or viral infections in the lungs, eg 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 (as in COPD) 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.

Airways infection 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

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.

Gastro-oesophageal reflux

Gastro-oesophageal reflux requires treatment with antacids to neutralise the stomach acid, or H2 antagonists or proton-pump inhibitors to reduce the production of stomach acid.

Smoking

Giving up cigarettes will lessen or abolish smokers' cough in 94 per cent of people within four weeks.

Go To Next Page>>



The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care or attention by a qualified practitioner. The materials in this web site cannot and should not be used as a basis for diagnosis or choice of treatment. Conditions for use



© Copyright 1998 - 2004 NetDoctor.co.uk - All rights reserved