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 gets into the lungs, they could become a breeding ground for bacteria and cause pneumonia or infection in the breathing tubes.
- Breathing in dust particles, smoke or some other irritant substance in the air can cause cough, or when a piece of food goes down the wrong way.
- Infections such as common cold, acute bronchitis, pneumonia, whooping cough and croup, are all infections of the lung, which cause cough.
- Conditions such as asthma, gastro-oesophageal reflux, post-nasal drip, pneumonia, acute heart failure, lung cancer or pulmonary embolism (a clot in the blood vessels of the lung) may all cause cough.
- Some people taking angiotensin converting enzyme inhibitors (ACE inhibitors), used in heart disease, may develop a dry cough.
A dry cough occurs because the throat and upper airways becomes inflamed, it is non-productive (phlegm is not produced). Dry coughs are usually felt in the throat as a tickle, which sets off the coughing.
Can be either productive (phlegm is produced) due to extra mucus produced as a response to infection or non-productive due to infection causing the lung passageways to swell. If a cough feels chesty but is non- productive, this should be described as a chesty cough; phlegm may be present but is not loose enough to be coughed up.
- The elderly, especially the frail, the malnourished and those who cannot keep warm are susceptible to chest infection. Such infections may make aged patients take to their beds where they may develop pneumonia.
- Infants are more likely to develop chest infections because they haven’t developed resistance to most of the viruses that cause them.
- Although wheezing (a tight noise when breathing out) is the classic symptom of asthma, many children’s major symptom is a cough. The cough is dry (non-productive) and often sounds tight. It tends to get worse at night, with exercise, or after being exposed to a trigger (e.g. cigarette smoke, animal hair, or house dust). Children with asthma often have a prominent cough when they catch a cold. Some children with asthma have wheezing with no cough; some have cough with no audible wheezing; and some have both. If a child with asthma has difficulty speaking or sleeping because of wheezing, cough, or shortness of breath, it is important to contact the doctor immediately.
- Smoking will exacerbate a cough and can cause coughing since it is irritant to the lungs. One in three long-term smokers develop chronic cough.
Sufferers of Gastrointestinal Reflux
- In individuals who suffer from gastrointestinal reflux, stomach acid coming back up the gullet and spilling over into the windpipe can cause dry cough.
Sinus infections and sufferers of sinusitis
- Drainage from nose or sinuses (post-nasal drip) can cause a dry cough in individuals who commonly suffer with sinus infections.
Individuals with heart failure
- An individual suffering from heart failure has a chesty with the sputum produced often described as “pink and frothy”. The individual would also be breathless (especially in bed and during the night) and have swollen ankles. Chest infections are more likely in individuals suffering from heart failure due to the build of fluids in the lung.
Those living or working in close quarters
- Viral and bacterial infections spread easily anywhere people gather – childcare centres, classrooms, offices, prisons and military installations.
A cough caused by a bacterial infection or a viral infection which has weakened immune response and resulted in a bacterial infection, leads to the production of green or brown mucus. If the mucus has not cleared after seven to ten days and particularly if you feel unwell you may need to take antibiotics to clear the infection. Coughs left untreated may also lead to the development of pneumonia.
- phlegm which is green, yellow or rusty colour, or containing blood
- coughing up blood
- cough lasting longer than two weeks
- shortness of breath
- chest pain on breathing or coughing
- unexpected loss of weight
- regular night time cough
- harsh barking cough in children (croup)
- whooping sound when breathing in after a fit of coughing (whooping cough)
One of the most important things to do, if you have a cold, is to look after yourself. Follow these self-care tips to make yourself as comfortable as possible:
- Smokers who get recurrent chest infections should seriously consider stopping smoking. If you are determined to continue smoking, at least stop for the duration of the cough to give the lungs an opportunity to try to clear the infection.
- Using steam inhalations helps to liquefy lung secretions and the warm, moist air is comforting. Menthol and eucalyptus can also help reduce congestion in a cough associated with a cold and one teaspoonful of it should be added to a pint of hot (but not boiling water). A cloth or towel can be put over the head to trap the steam.
- Keeping a high fluid intake helps to hydrate the lungs and hot drinks can have a soothing effect. If you have a cough or a cold, increase your fluid intake by around two litres a day.