Persistent Cough: Why Won't My Cough Go Away?

A cough lingering for weeks is one of the commonest reasons to seek medical advice. A guide to the causes, from postnasal drip and reflux to asthma and medication, plus when to get a persistent cough checked.

A cough is one of the body's natural defence mechanisms, helping to clear irritants, mucus and other unwanted material from the airways. Most coughs are short-lived and settle within a few weeks. However, when a cough persists, it can become frustrating, exhausting and sometimes concerning. A persistent cough is a common reason for seeking medical advice. Although many cases have relatively straightforward causes, an ongoing cough should not simply be ignored, particularly when it affects sleep, work or everyday activities. At the Oving Medical Clinic, we're aware of the importance of identifying the underlying cause of a persistent cough and providing an appropriate assessment and treatment plan. When Does a Cough Become Persistent? A cough is generally classified according to how long it has been present: - Acute cough: Lasting less than three weeks. - Subacute cough: Lasting between three and eight weeks. - Chronic cough: Lasting more than eight weeks. A cough following a viral respiratory infection can sometimes linger for several weeks. However, a cough lasting longer than three weeks, particularly without signs of improvement, warrants consideration of a medical assessment. What Causes a Persistent Cough? There are several possible causes of a persistent cough. Identifying the underlying problem is important because treatment will depend on the cause. 1. Postnasal Drip One of the common causes of persistent cough is postnasal drip, also known as upper airway cough syndrome. This occurs when mucus from the nose and sinuses drains down the back of the throat, irritating the sensitive tissues and triggering coughing. Postnasal drip may be associated with allergic rhinitis, chronic sinusitis or other nasal conditions. An ENT assessment can help identify whether nasal or sinus problems are contributing to the cough. 2. Acid Reflux (Gastro-oesophageal Reflux Disease) Acid reflux occurs when stomach contents travel upwards into the oesophagus. In some people, this can irritate the throat and voice box, triggering a persistent cough. Interestingly, reflux-related coughing does not always occur alongside typical heartburn. Other symptoms may include: - A persistent sensation of something in the throat. - Frequent throat clearing. - Hoarseness or voice changes. - An unpleasant taste in the mouth. - Coughing after meals or when lying down. 3. Asthma and Airway Sensitivity Asthma is an important cause of persistent cough. Some people experience predominantly coughing rather than the more familiar symptoms of wheezing and breathlessness. Symptoms may include coughing at night, during exercise, in cold air or following exposure to allergens. Assessment by a GP may be appropriate. 4. Persistent Infection or Post-Viral Cough Following a respiratory infection, the airways can remain sensitive for several weeks. Even after the original infection has resolved, minor irritants such as cold air, talking or physical activity may trigger coughing. Other infections, including whooping cough (pertussis), can also cause prolonged episodes of coughing. 5. Medication-Related Cough Certain medications can cause a persistent dry cough. A well-recognised example is ACE inhibitors, a group of medicines commonly prescribed for high blood pressure and cardiovascular conditions. If a medication is suspected, it may be appropriate to discuss this and be reviewed by a GP. 6. Other Causes Other conditions that may contribute to a persistent cough include: - Chronic obstructive pulmonary disease (COPD). - Smoking-related airway irritation. - Bronchiectasis. - Interstitial lung disease. - Less commonly, more serious respiratory conditions. It is important to consider the wider clinical picture rather than assuming that every persistent cough has a simple explanation. When Should You Seek Medical Advice? You should arrange a medical assessment if your cough has lasted longer than three weeks, is worsening, or is interfering with your daily activities. Certain symptoms require more urgent investigation. These include: - Coughing up blood. - Unexplained weight loss. - Persistent or unexplained breathlessness. - Chest pain. - Persistent fever or feeling significantly unwell. - A persistent change in cough, particularly if you have a history of smoking. Severe difficulty breathing, significant chest pain or coughing up more than small streaks of blood requires urgent medical attention. How Is a Persistent Cough Investigated? The first step is a careful medical history and examination. Depending on the findings, investigations may include: Chest X-ray: To look for underlying lung or chest conditions. Lung function testing: To assess for asthma or other respiratory conditions. Allergy assessment: Where allergic rhinitis or environmental triggers are suspected. ENT examination: To assess the nose, sinuses, throat and voice box. A flexible nasendoscopy may sometimes be recommended. This involves passing a very fine flexible camera through the nose to examine the back of the nose, throat and larynx (voice box). It is usually performed in the outpatient setting and is offered by Dr Wang. Don't Ignore a Persistent Cough Most persistent coughs are caused by conditions that can be successfully managed once identified. However, continuing to treat the symptom without investigating its cause may delay appropriate treatment. If you have a cough that is not settling, particularly if it has lasted longer than three weeks, seeking medical advice is a sensible first step. At the Oving Medical Clinic, we offer assessment of a range of ENT conditions and can help investigate potential upper airway causes of persistent cough. Dr Wang is well placed to help in this area with a background in both ENT and general practice. If you are concerned about an ongoing cough, contact us to discuss whether an ENT/GP consultation may be appropriate. Medical disclaimer: This article is intended for general information and does not replace an individual medical assessment. If you are breathless, coughing up blood or feeling significantly unwell, seek urgent medical advice.