A persistent cough – or one that seems to be getting better only to return – can have many different causes, most of which are nothing to worry about. However, because it could also be a sign of something more serious, it’s important to get it checked out.
What is a chronic cough?
A cough that lasts eight weeks or longer is called a chronic cough (in children it’s four weeks).
What are the common causes of a chronic cough?
Common causes of a persistent cough include:
- Post-nasal drip: This results in mucus dripping down the back of your throat, triggering the cough receptors. Lingering symptoms from a cold, as well as hay fever or sinusitis can all cause post-nasal drip, and it is often worse at night when you lie down.
- Gastro-oesophageal reflux disease (GORD): This leads to acid from your stomach travelling up the oesophagus, irritating the airways or triggering a nerve reflex. It can lead to a persistent cough without, necessarily, producing classic ‘heartburn’ symptoms.
- Asthma: With cough-variant asthmas, a cough is the primary symptom. It can be triggered by cold weather or exposure to certain chemicals or fragrances. This type of cough can also follow an infection of the upper respiratory tract.
- Airway inflammation after an infection: If you’ve had an infection, such as a cold, flu, pneumonia or Covid-19, your respiratory tract can remain inflamed, leading to bouts of coughing. These can be triggered by many different factors including cold air or even talking. A chronic cough can also be associated with fungal infections of the lung or lung infections linked to exposure to bacteria found in dust, soil or water.
- Chronic obstructive pulmonary disease (COPD): This incurable condition causes inflammation which limits airflow from the lungs. COPD includes chronic bronchitis and emphysema. Most people who have COPD are or were previously smokers.
- Blood pressure drugs: One of the possible side-effects of angiotensin-converting enzyme (ACE) inhibitors – which are prescribed for high blood pressure and heart failure – is a chronic cough.
- Smoking: The classic ‘smoker’s cough’ develops when your lungs produce mucus to try and get rid of the harmful chemicals and particles in tobacco smoke. A smoker’s cough can lead to COPD.
What are some of the less common causes of a chronic cough?
There are also some less-common reasons why you might develop a persistent or recurrent cough. These include:
- Cystic fibrosis: This is a genetic disorder that affects the lungs, digestive system and other organs.
- Lung cancer: This includes non-small cell lung cancer and small cell lung cancer. Smoking is the leading cause of lung cancer, although it can also develop in people who have never smoked.
What to do when you have a chronic cough
When you cough, your vocal cords come together forcefully. This can lead to irritation and the production of mucus, which can trigger more coughing. It can be difficult to break this cycle. Try controlling your cough reflex using the ‘hold, blow, sip, swallow’ technique:
- Hold your breath for a count of five
- Blow out of your mouth as if you were blowing out a candle
- Sip some water
- Swallow with your chin tucked down towards your chest
Having a persistent cough can be very tiring and it may affect your sleep, as well as leading to complications such as headaches, dizziness, broken ribs or fainting. It’s important to get a diagnosis as a persistent cough can sometimes be a sign of a serious underlying condition.
Contact us for advice on diagnosing and treating persistent or recurrent coughs.
Frequently Asked Questions
How is a persistent cough diagnosed?
Your doctor will ask about your medical history and carry out a physical examination. You may be sent for imaging tests to rule out conditions such as lung cancer, pneumonia or other lung infections. Spirometry is a test that assesses your lung function, measuring how much air your lungs can hold and how fast you can exhale. It is used to diagnose asthma and COPD.
What treatments are there for a persistent cough?
The treatment will depend on what is causing your cough. If you smoke, quitting may be one of the most effective ways of tackling your cough. If you have allergies or post-nasal drip, decongestants, corticosteroids or antihistamines may provide relief. Inhaled medication is prescribed for an asthma-related cough, while bacterial, fungal or mycobacterial infections are normally treated with antibiotics. GORD can be managed with lifestyle changes, medication to block acid production or, rarely, surgery.
Should I use cough suppressants?
A cough suppressant is a type of medication that can reduce coughing. While it’s important to get to the bottom of what’s causing your cough, a cough suppressant may provide short-term relief from symptoms. Cough suppressants are not recommended for children.