Cough: dry cough

A dry cough is a cough where no phlegm or mucus is produced (known as non-productive). A dry cough is irritating, usually with a tickly throat.

How long does a cough normally last?

Coughs associated with a cold or the flu tend to last a week or 2, most clearing up within about 3 weeks. A post-viral cough may persist for several (up to about 8) weeks after a viral illness, while some coughs persist for longer and are usually a sign of an underlying problem.

In adults and children, a cough is described as acute (short term) if you have been coughing for up to 2 weeks.

In adults, a cough that lasts for more than 8 weeks is described as a chronic (ongoing) persistent cough.

In children, a cough that lasts 2 to 4 weeks is called a prolonged acute cough. A cough that lasts more than 4 weeks is considered to be a chronic cough.

Causes of dry cough

A dry cough is often the result of:

  • a viral illness, such as a cold or influenza (the flu); or
  • a post-viral, or post-infective, cough (cough that persists for weeks after a viral illness).

However, a dry cough may be a result of other problems, such as:

  • asthma;
  • gastro-oesophageal reflux;
  • smoking;
  • allergic rhinitis (hay fever) due to inhaling substances you are allergic to, such as pollen, dust or pet dander;
  • post-nasal drip (the drainage of mucus secretions from the nose or sinuses down the back of the throat);
  • laryngitis (inflammation of the larynx, also known as the voice box);
  • whooping cough;
  • obstructive sleep apnoea and snoring;
  • habit cough (a cough that is only present in the daytime and not caused by illness – it most often affects school-aged children);
  • certain types of lung disease known as interstitial lung disease; or
  • a side effect from a medicine (for example, cough is a possible side effect of most ACE inhibitors – often prescribed for high blood pressure).

Other, less common, causes of a dry cough include:

  • heart failure;
  • pulmonary embolism (a blood clot in the lungs); or
  • lung cancer.

A dry cough can be aggravated by:

  • breathing cold, dry air;
  • air pollution;
  • inhaled irritants such as dust or smoke;
  • exposure to tobacco smoke;
  • excessive use of your voice; or
  • a change in temperature.

Complications

A persistent dry cough can cause problems, including the following complications.

  • Repeated coughing can lead to urinary incontinence in women, especially older women, pregnant women and those who have been pregnant.
  • Interrupted sleep resulting in tiredness is a common problem for people with a persistent cough.
  • Severe or uncontrollable coughing fits can sometimes cause vomiting.
  • Headaches may result from a persistent cough.

Can I hurt myself coughing?

When a cough is severe, pulled chest muscles and even fractured ribs are a possible complication.

Diagnosis and tests

Your doctor will ask about your cough and any other symptoms you may have, and perform a physical examination. Depending on your age, history and examination, your doctor may order tests such as:

  • a chest X-ray;
  • a throat swab (sample of secretions from the back of your throat which can be tested for infections);
  • lung function tests; or
  • allergy tests.

Dry coughs are often related to a viral illness and in most cases special tests are not needed.

When should you seek medical advice about a dry cough?

You should you seek medical advice if:

  • you start to cough up blood or copious amounts of mucus (phlegm);
  • you are short of breath or wheezy;
  • the cough is mainly at night;
  • you have associated chest pain;
  • you have a fever;
  • you are a cigarette smoker;
  • you have a hoarse voice;
  • the cough is associated with vomiting or a choking sensation;
  • you have other symptoms such as an ongoing headache, sore ears or a rash;
  • you have recently lost weight or have general muscle aches;
  • the cough is in an infant aged 6 months or younger;
  • the cough has lasted longer than 10 days, with little or no improvement; or
  • you have high blood pressure, a heart complaint, respiratory illness (such as asthma), gastric problems or are taking other medicines.
Last Reviewed: 24 February 2016
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References

1. Cough (revised February 2015). In: eTG complete. Melbourne: Therapeutic Guidelines Limited; 2015 Nov. http://online.tg.org.au/complete/ (accessed Feb 2016).
2. Royal Children’s Hospital Melbourne. Kids Health Info: Cough (updated Dec 2012) http://www.rch.org.au/kidsinfo/fact_sheets/Cough/ (accessed Feb 2016).
3. MayoClinic.com. Cough (updated 24 May 2013). http://www.mayoclinic.org/symptoms/cough/basics/definition/sym-20050846 (accessed Feb 2016).
4. NHS Choices. Cough (updated 1 May 2015). http://www.nhs.uk/conditions/cough/pages/introduction.aspx (accessed Feb 2016).
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