It's one of the most common medical complaints, and each year many thousands of people – up to 10% of the population by some estimates – seeks their doctor's help for it. Often, however, using one or two natural treatments may be all that's necessary to relieve a troublesome cough.

What is it?

Despite its seemingly unhealthy sounds, a cough is a vital bodily function. Even though you may not realise it, you probably cough once or twice every hour to clear your throat and air passages of debris. Coughing causes trouble only when an environmental substance or an illness makes you hack uncontrollably. Coughs can be dry and nonproductive, meaning that they bring up no fluids or sputum; or they can be wet and productive, expelling mucus and the germs or irritants it contains.

What causes it?

When an irritant enters your respiratory system, tiny cough receptors in the throat, lungs and air passages begin producing extra mucus. This stimulates nerve endings and starts a sequence that culminates with the forceful expulsion of air and foreign material through the mouth – the cough. A variety of factors can trigger this reaction. Bacteria or viruses such as those that cause flu or the common cold lead to overproduction of mucus, which can irritate a cough refex (particularly at night, when the sinuses drain into the throat and set off tickly coughs.) Asthma, bronchitis, hay fever and environmental pollutants such as cigarette smoke, chemicals or perfume are other culprits.

Heartburn can also provoke a cough (when stomach acid rises into the oesophagus, burning and irritating the throat). Coughing can also be a side effect of certain prescription medications, especially those that are used to treat high blood pressure. Less commonly, persistent coughing can result from a tumour in the lungs, throat or voice box, or from fluid in the lungs caused by congestive heart failure.

What are the symptoms?

  • A cough is really a symptom – usually an indication of a respiratory infection or irritation of the throat, lungs or air passages.
  • A cough can be wet (productive) or dry (nonproductive).

Are there any natural therapies?

Natural cough remedies can be used in place of over-the-counter medicines. There are two primary goals in treating a cough: to subdue the cough reflex, especially when a cough causes pain or interferes with sleep; and to thin the mucus, making it easier to bring up so the irritant can be flushed from the body.

The herb slippery elm will soothe the throat and suppress dry coughs. When steeped in water, marshmallow release mucilage, a gel-like plant substance that coats the throat and larynx and calms the cough receptors. If you prefer, you can substitute mullein flowers; these also contain mucilage. Adding some licorice to the tea will loosen phlegm and relax bronchial spasms. (Using licorice for more than a month can raise blood pressure.) Horehound in tea form has the same benefit as licorice, but doesn't raise blood pressure. Combinations of these herbs may be available commercially as tea bags. If you don't like the tea, try tinctures of these herbs. Follow the package directions or add the tincture you're using to a small glass or warm water and drink three times a day.

Inhaling steam from hot water suffused with a few drops of eucalyptus or peppermint oil can open clogged sinuses, clear respiratory passages and minimise bronchial spasms. Cough drops or hard lozenges containing eucalyptus, peppermint, anise or fennel increase saliva, causing you to swallow more – which also suppresses the cough reflex.

What else can I do?

  • Drink lots of fluids – water, broth and juices – to help thin the mucus.
  • Use a cool-mist vaporiser or a humidifier to moisten the air.
  • Don't smoke, and avoid contact with irritating fumes or vapours.

Did you know?

The herb ribwort, a member of the plantain family, is an effective cough remedy. However, the TGA warns that many products claiming to contain plantain in fact contain digitalis, a substance that can cause heart abnormalities. Don't use products labelled 'plantain' unless the botanical name (Plantago lanceolata) is given.