Mechanism of cough
complex interaction of nerve fibres. There are a lot of receptor sites situated in the nose, nasopharynx, larynx, auditory canal, trachea, pulmonary bronchus and pleura. They report about the excess mucous or foreign substance to the cough center which is located in the medulla of the brain for inducing cough. Receptors are sensitive to
- Touch of inhaled foreign body
- Excessive secretions or mucous in nose, throat, sinuses and lungs
- Irritant gases like nitric acid, sulphuric acid, ammonia
- Oedema or infection with pus in the airway
- Exposure to extreme hot or cold air
- Productive cough – Also named as an effective cough since it brings secretions or mucous from the lungs. This type of cough is mostly acute in nature and often caused by bacterial or viral or fungal infection. This type of cough should not be suppressed or otherwise recurrent or constant infection will be there, since the purpose of the cough (to remove mucus) is suppressed.
- Non-productive cough – Also named as an ineffective cough since it won’t bring any secretions or mucous from the lungs. It is a dry, irritating cough without phlegm. Mostly, this type of cough is chronic in nature and caused by dry irritation or dust or smoke or fumes, or due to oedema and mild secretion in the resolving stage of illness. It may be also due to weakness of the muscles of respiration, thick viscid mucus and in diseases of the cilia which helps mucous transportation in the airway.
Cough can also be classified as:
- Acute – not more than three weeks’ duration – for example, infective coughs
- Chronic – more than three weeks’ duration – for example, smoker’s cough
- Dry cough – No mucous or secretions &
- Wet cough – with mucous or secretions
- Cough from chest and cough from throat – Productive or non-productive
- Paroxysmal cough – spasmodic and recurrent
- Bovine cough – soundless cough due to paralysis of larynx
- Psychogenic cough – self-conscious activity of the patient to draw attention
Causes of cough
Ear – Otitis media, CSOM, impacted cerumen and foreign body
- The anus will get tightly closed – so it may aggravate piles or fissure in the anus.
- Pressure in abdomen is increased – so hernia may occur in diaphragm or the muscle of the abdomen (umbilical hernia, incision hernia, etc.) or into the scrotal sac
- Due to pressure in chest – air emphysema may develop
- Due to violent cough, bursting type of headache may occur
Sputum also gives a clue to diagnosis with quantity, consistency, colour, odour and thickness. Purulent sputum indicates pneumonia, bronchitis
Blood-stained indicates tuberculosis or pneumonia
Yellow or green sputum with odour indicates the presence of bacterias, leucocytes and pus.
Cough with pain
- Pain in head, face and maxillary tooth is sinusitis
- Burning pain in chest with sour eructation is gastro esophageal reflux
or tracheal obstruction
Psychogenic cough – the diagnosing point is these patients won’t cough at night.
Ø Working in areas of noxious fumes or polluted air
Ø Cold food items
Ø Contact with infected persons or wear a protective mask
Ø Continuous usage of nasal decongestant sprays and cough syrups
Ø Plenty of fluids – water, juices to dilute mucous for easy expulsion
Ø Frequent light and small meal to reduce vomiting in oesophageal reflux
Ø Steam inhalation to loosen the phlegm
Ø Vitamin C and zinc to shorten the duration of cold or disease
Also there are two types of drugs used to treat cough:
secretions from the airways. These medications help to thin bronchial secretions and make them looser and easier to cough up. Steam inhalation also helps make secretions looser and easier to cough up.