WHAT CAUSES

A COUGH?

Most coughs are caused by colds or flu. Other causes can include smoking, heartburn, allergies (hay fever, for example), infections such as bronchitis, mucus dripping down the throat from the back of the nose and – very rarely, something more serious. It should clear up on its own within three to four weeks.¹

A cough is a reflex action to clear away a foreign particle from the airway. The mechanics are complex, involving the nervous system the bronchial tree and the stomach muscles. The reflex starts when receptors in the body’s vagus nerve are stimulated. A full inhale almost fills the lungs, the glottis at the back of the throat closes and the stomach walls contract. The glottis opens suddenly, with an upward heave of the diaphragm, and air is sent out at the rate of up to 600 (95km) an hour. Three different stomach muscles force out the air. If stomach muscles are weak, the cough isn’t as effective.²

Although coughs are typically caused by common colds, flu or bronchitis, there are other reasons such as smoke, dust and the drying effects of air conditioning which can all irritate the airways and bring on a cough. Also, an allergic condition known as rhinitis. And some medicines (ACE-inhibitors, for example, prescribed for the treatment of high blood pressure or cardiovascular disease). In children, a persistent cough can indicate a more serious respiratory tract infection such as whooping cough.³

THE

DIFFERENT KIND OF COUGHS

Coughs that are acute and short term tend to be caused by infection to the upper respiratory tract, which affects the throat. This is known as a URTI or URI. Typical examples are flu, a common cold or laryngitis.

Infection to the lower respiratory tract affects the lungs and/or the airways lower down from the windpipe. Typical examples of this are bronchitis or pneumonia.

Chronic, longer-lasting coughs can be caused by smoking, asthma, mucus dripping down from the throat to the back of the nose, and some medications.⁴

A chesty or mucus cough is sometimes called a ‘productive’ cough, when coughing is your body’s way of getting rid of mucus in the chest.

An expectorant cough medicine can help loosen the mucus for easier coughing⁵

This type of cough produces yellow-grey mucus or phlegm and is normally accompanied by cold-like symptoms such as stuffy nose, headache, and fatigue.

The best treatment is rest and fluids, which can prevent dehydration and also thin the mucus.

Antibiotics aren’t suitable for most people with bronchitis, because the condition is usually caused by a virus, not a bacterial infection.⁵

A dry and tickly (non-productive) cough is when the throat doesn’t produce any mucus or phlegm, resulting in irritation. It feels tickly, hence its name.

A demulcent can coat the throat and relieve irritation in the upper respiratory tract.

Demulcents can include water, hard candy, lemon, honey, menthol or a simple syrup.⁵

A post-viral cough can commonly appear after an upper respiratory tract infection due to throat inflammation. It’s rarely bacterial.

Cough syrup (with either dextromethorphan or menthol) can help to relieve discomfort.⁵

WHEN TO

VISIT YOUR GP

A cough will usually clear up on its own within three to four weeks, you shouldn’t need to see a GP.

you’ve had a persistent cough lasting more than 3 weeks

your cough is very bad or quickly gets worse

you’re pregnant

you’re finding it hard to breathe

you feel very unwell

your immune system is weak, through chemotherapy for example

you have chest pain

you’re coughing up blood - this is very urgent

you’re losing weight for no reason