What and Why?
Of all the parts of you that are exposed directly to the outside, the skin of your lungs is far the most delicate and vulnerable. Yet it devotes hardly any effort to self-defence, concentrating entirely on its highly specialized function of exchanging gases between the air and your blood. For its protection it relies on the efficiency of the air conditioning in your nose, and other defences in your voice-box and wind-pipe through which the air must pass to reach your lungs in the first place. Coughing is an important part of those defences.
Your nose and throat join in your pharynx (a short vertical tube from the back of your nose into the top of your neck), so that you can by-pass your nose when breathing hard. Just below that your wind-pipe begins, with two curtains of elastic skin drawn across it to act as vocal cords and sluice-gates. They can shut tight to keep out food and sea-water, but that stops you breathing too — not practical except in extreme emergencies. Routinely they protect your lungs in a more dynamic way. Your vocal cords close briefly when you swallow food, which does not even touch them so that fragments do not drip through afterwards.
But you make mistakes sometimes, especially with drinks, and there is often a little mucus or moisture to be cleared out of your lungs. To deal with these you almost close your vocal cords, then blow out hard. For a split second air roars through the narrows at gale force, carying all before it. That is coughing, a natural protective function quite healthy in itself. ‘Clearing your throat’ is normal, but you need to understand why you sometimes cough too much.
The usual problem is that uncomfortable air is still getting through, despite the best your nose can do. In cold weather it may simply be too chilly and dry, shocking your wind-pipe as well as your face. More often, irritant gases, airborne chemicals and smoke penetrate to your vocal cords from overwhelmingly polluted air: coughing is your reasonable but ineffectual attempt to protect yourself.
Colds, asthma, hay fever and catarrh can spread to your vocal cords and wind-pipe, making them touchy. Mucus from an inflamed wind-pipe needs clearing anyway, so some of the coughing is useful: most is not. Hoarseness and loss of voice often accompany the cough.
Least common is what you may be most expecting, the cough that indicate bronchitis, tuberculosis or lung cancer. Any chest infection is likely to make you very breathless, or produce lots of sputum (pus) from your chest — tablespoonsful each day, probably a dirty colour. The vast majority of coughs at any age arise from above or around your vocal cords, not deep inside them.
The cough of pertussis (whooping cough) is highly characteristic and usually gives the disease away — a prolonged run of explosive coughing which exhausts all the air from your lungs and leaves you blue and desperate for air: the long whooping sound follows as the air sighs gratefully back in. Retching or actual sickness commonly accompany or follow the coughing. All this is caused by chemical poisoning of the nerves in the skin of your wind-pipe by a toxin that is made by the pertussis germ. This toxic effect may outlast the actual infection by many months.
What can I do?
Advice to maintain and maximise health
1. Steer clear of smokers and smoking, still the largest avoidable cause of coughing. Uphold smoking bans in public places if you see them defied. Never let anyone smoke near your children, and ventilate any smoking-place well.
2. Practise breathing deeply every day, in the freshest air you can find. Always inhale through your nose to take advantage of its air conditioning power, and exhale through your mouth.
3. Muffle your face and throat in cold weather, to re-breathe some of your exhaled air. This saves you warming and moistening every breath from scratch. Ventilate your bedroom at night but cover your face well with warm bedding, to achieve the same effect.
4. Mask your face effectively during any dusty DIY job. Choose muscle-power over chemicals and engines every time, but ventilate any fumes thoroughly to the outside. Never run the car for long in an enclosed space.
5. Humidify insulated, draught-proofed and centrally heated places with flowers, pot plants, a fish-tank or radiator accessory. An air ionizer may be helpful in high-tech or smoky rooms.
6. The best first aid for cough is steam, inhaled slowly and deeply through your mouth and exhaled through your nose. Cover the jug of hot water with a cloth held across your upper lip and cheeks, to confine the steam but leave your eyes free. Five minutes’ inhalation every hour is the highest useful dose. Menthol and Eucalyptus Inhalation, Karvol or Olbas oil on a clean handkerchief, kept in a warm pocket ready to inhale whenever you feel a tickle coming on, is almost as good for use away from home, and safer for small children.
7. A night light candle under a pan of hot water containing one teaspoon (5ml) of Menthol and Eucalyptus Inhalation makes a cheap and effective vaporizer to run in the victim’s bedroom. Wright’s Vaporizer unit is more expensive but works on a different principle: try that next if all else fails.
8. Cough Drops (Weleda UK Ltd) are a useful and safe alternative to cough linctus, but are only available on private or NHS prescription. The Honey Cider Vinegar recipe makes a wholesome substitute for cough syrup. Pholcodine (or Codeine) Linctus is the only conventional cough suppressant that is really effective, but it makes many people constipated. Homoeopathic remedies vary widely according to your detailed symptoms, so get further advice from a competent practitioner.
9. One or two drugs prescribed to control blood pressure can cause very stubborn coughing as a side effect. Ask your doctor if you think this may apply to you.