Coughing is a symptom that usually indicates irritation of the lungs by some process, most commonly infection. However, many other factors may cause cough including inflammation, scarring, cancer, reflux of acid from the stomach, postnasal drip, side-effects of drugs and hypersensitivity of the back of the throat. Smoking is a very common cause of cough.
Here, one of our top consultants in respiratory medicine Dr Dan Ornadel explains the different types of cough, their accompanying symptoms, and when it might be time to see a doctor.
How are different types of coughs determined?
Coughing is usually self-limiting and stops by itself in a short time. If a cough has persisted for more than three weeks, a patient is advised to consult their doctor. The doctor will take a careful account of how it developed, examine you and advise whether any further investigations or treatment are needed.
How does a wet cough differ to a dry cough?
A wet cough is productive of sputum, which may be clear, white, grey, yellow or green. Sometimes the sputum may contain blood which can be bright red (fresh) or dark (old). A dry cough is generally unproductive of any sputum.
What are the other types of cough and their accompanying symptoms?
Coughs differ considerably in their nature and frequency. Descriptive terms such as dry, barking or hacking are often used. The nature of the cough does not usually help to identify the underlying cause, except perhaps for the classic 'whoop' heard in whooping cough.
Coughs may occur at certain times of the day or night, for example, when lying down. Coughs may occur sporadically in short bursts or spasms or they may seem to be almost continuous. They may also be provoked by certain actions, commonly exercise, laughing or talking, or by environmental factors such as cold air, air conditioning, change of season or environment (such as moving from warm to cold or vice versa) and allergens (for example hay fever).
Depending on the cause, a cough may be associated with other symptoms including breathlessness, wheeze, fever, chest pain, fatigue, loss of appetite, weight loss, retching or vomiting, rashes, joint pains and other symptoms.
What are the possible illnesses that coughing could be a symptom of?
Most coughs are caused by a virus and are usually short-lived. For example, many people cough for a few days with a cold and then it goes away. There are too many other causes of cough to list here but serious causes to exclude include:
- Lung cancer
- Secondary cancer - which has spread to the lungs
- Pulmonary fibrosis
- Pleural effusion
- Lung collapse - secondary, for example, to inhaling a small object by a child
- COPD and cryptogenic organising pneumonia, among others
- ACE inhibitors - used to treat high blood pressure and are a classic drug-related cause of cough.
Other common causes of a chronic cough include asthma, gastric reflux, post-nasal drip, bronchitis (often smoking-related) and upper airway cough syndrome.
When should I see a doctor?
Most coughs will resolve by themselves in a few days or at most, weeks. If the cough has lasted for three weeks or more then you should consider visiting your doctor. Other warning signs before three weeks might include thick green or yellow sputum, coughing blood, fever, chest pains and breathlessness for which you should consider seeking help sooner.
Book an appointment with Dr Ornadel now if you would like treatment for a persistent cough.