What Is a Cough?
A cough is a reflex action that helps clear your airways of irritants, mucus, or foreign particles. It is a vital defence mechanism used by your body to protect the lungs and maintain healthy breathing. There are different types of coughs, including dry and productive (phlegmy) coughs, but all serve the same purpose – to clear the airways.
Why Do We Cough?
Coughing is triggered when sensors in the throat, airways, or lungs detect an irritant. These sensors send signals to the brain, which in turn signals the muscles in your chest and abdomen to contract, causing a burst of air to be expelled from the lungs. This action helps remove the irritant from the airways.
Acute and Chronic Cough: What’s the Difference?
Coughs can be classified into two main types based on how long they last: acute and chronic.
Acute Cough
An acute cough is a short-term cough that typically lasts less than three weeks. It is usually a symptom of an underlying condition, often related to an infection or irritant. Acute coughs are common and may resolve on their own once the underlying cause is addressed.
Causes of Acute Cough
The most common causes of acute cough include:
- Common Cold: Viral infections such as the cold often lead to a dry or wet cough as the body tries to expel mucus from the airways.
- Flu (Influenza): A flu infection can cause a dry, persistent cough that may last several days.
- Acute Bronchitis: Inflammation of the airways, often due to infection, can result in coughing, particularly productive cough with mucus.
- Allergies: Exposure to allergens like pollen, dust, or pet dander may trigger coughing.
- Irritants: Smoke, pollution, or strong smells can lead to temporary coughing as the body tries to clear the irritants from the throat and lungs.
Chronic Cough
A chronic cough lasts more than eight weeks in adults and four weeks in children. It can be a sign of a more serious underlying condition and may require medical evaluation. Chronic coughs are not only disruptive but can also indicate long-term lung or airway problems.
Causes of Chronic Cough
Several conditions can cause chronic cough, including:
- Asthma: Often characterised by wheezing and difficulty breathing, asthma can cause a chronic dry cough, particularly at night.
- Chronic Obstructive Pulmonary Disease (COPD): Conditions such as chronic bronchitis and emphysema fall under COPD and can cause persistent coughing.
- Gastroesophageal Reflux Disease (GORD): Stomach acid travelling up into the oesophagus can irritate the throat and cause chronic coughing, especially after eating or lying down.
- Postnasal Drip: Excess mucus dripping down the back of the throat can cause irritation, leading to chronic cough.
- Smoking: Long-term smoking irritates the airways and leads to a “smoker’s cough.” Even after quitting, the cough may persist for some time as the body clears the lungs.
Diagnostics and Treatment
Diagnosing the cause of a cough involves a combination of patient history, physical examination, and sometimes further testing. Determining whether a cough is acute or chronic is the first step in guiding the diagnosis.
Diagnosing Acute Cough
In cases of acute cough, a doctor will usually start by reviewing symptoms and medical history. A physical examination may include listening to the lungs using a stethoscope to check for wheezing or crackling sounds. In some cases, a chest X-ray may be necessary to rule out more serious conditions, such as pneumonia.
Diagnosing Chronic Cough
For chronic coughs, more thorough diagnostic tools may be required. These can include:
- Chest X-ray or CT Scan: These imaging techniques can help identify issues such as lung infections, tumours, or structural problems in the lungs.
- Spirometry: This test measures lung function and is often used to diagnose asthma or COPD.
- Endoscopy: An endoscope is inserted into the airways or oesophagus to look for signs of GORD or other abnormalities.
- Allergy Testing: This may be performed if an allergic reaction is suspected to be the cause of the cough.
Treatment Options
Treatment for a cough depends on its underlying cause. In most cases, addressing the root problem will alleviate the cough.
Treatment for Acute Cough
- Over-the-Counter Medications: For acute coughs due to colds or mild infections, over-the-counter medications, such as cough syrups or lozenges, can help soothe the throat and reduce coughing.
- Hydration and Rest: Staying hydrated helps thin mucus, making it easier to expel. Resting also allows the body to recover from infections.
- Steam Inhalation: Breathing in warm, moist air can help open the airways and relieve coughs caused by congestion.
- Avoid Irritants: For coughs triggered by smoke, pollution, or allergens, avoiding the irritant can often alleviate symptoms.
Treatment for Chronic Cough
- Medications for Underlying Conditions: If asthma, GORD, or COPD is diagnosed, specific medications are often prescribed. For asthma, inhalers are commonly used. GORD is treated with antacids or proton pump inhibitors, while COPD may require bronchodilators or steroids.
- Lifestyle Changes: Quitting smoking is essential for chronic coughs caused by smoking. Dietary changes may help those with GORD, while managing allergens can reduce coughs from postnasal drip.
- Physiotherapy for Cough: In some cases, physiotherapy can teach patients techniques to help clear mucus from the airways more effectively.
- Surgical Options: Rarely, surgery may be necessary for structural problems or severe cases of GORD that do not respond to medication.
Home Remedies
In addition to medical treatments, several home remedies can help relieve a persistent cough:
- Honey: Taking a spoonful of honey can help coat the throat and reduce irritation.
- Ginger Tea: Ginger has natural anti-inflammatory properties that can soothe the throat.
- Saltwater Gargle: Gargling with warm saltwater can help reduce throat inflammation and clear mucus.
When to See a Doctor
While many coughs resolve on their own, it’s important to see a doctor if the cough lasts longer than three weeks, or if it is accompanied by serious symptoms such as:
- Shortness of breath
- Chest pain
- Coughing up blood
- High fever
- Unexplained weight loss
Early diagnosis of a chronic cough can prevent complications and improve the outcome of any underlying conditions.