Six reasons why you may be coughing so much

Coughing is a natural reflex and defense against dust and bacteria. However, a cough can also be a sign of an underlying health condition affecting your respiratory system, which may need treatment if it’s affecting your quality of life or is associated with other serious symptoms.

Here we’ll look at the six most common causes of a cough.

1. Infection

An infection of your respiratory tract is the most common cause of an acute cough, that is, a cough that lasts fewer than three weeks. 

A respiratory tract infection can affect your upper respiratory tract (ie your sinuses and throat), such as a common cold, sinusitis, tonsillitis and laryngitis, or your lower respiratory tract (ie your airways and lungs), such as bronchitis, bronchiolitis, a chest infection and pneumonia.

In most cases, respiratory tract infections resolve within several days with or without treatment. Cough tends to last a little longer after the rest of the symptoms of a chest infection resolve.   

2. Asthma

Asthma is the most common cause of a chronic (long-term) cough, that is, a cough that lasts eight weeks or more. 

Asthma occurs when the airways of your lungs become inflamed and swell, which leads to breathlessness, wheezing and chest tightness. It is an inflammatory condition that is more common in people with allergies, such as hay fever and allergic eczema. 

Asthma attacks can be triggered by an infection, exposure to dust, pollen or animal dander, and hot humid weather. The cough produced as a result of asthma is a dry (nonproductive) cough, which means no sputum is coughed up. It is often associated with chest tightness and wheezing. 

3. Structural lung abnormalities 

Structural lung abnormalities include conditions such as bronchiectasis and less commonly, lung cancer.  

Bronchiectasis refers to an abnormal dilatation (widening) of your airways. It causes a wet (productive) cough with yellow, green and/or brown sputum. It also leads to frequent chest infections.  

4. Pulmonary fibrosis

This refers to scarring and thickening of the walls of the air sacs (alveoli) that make up your lung tissue, through which oxygen is absorbed and carbon dioxide is expelled. 

This disease gets worse over time and there is currently no cure. Risk factors for pulmonary fibrosis include smoking, working in an environment with high levels of dust or fumes, and ageing, as pulmonary fibrosis is more common in those aged over 50. 

Alongside breathlessness and fatigue, it can cause a persistent, dry cough. 

5. Gastroesophageal reflux disease (GORD)

GORD is a long-term condition that involves frequent acid reflux and heartburn. Acid reflux refers to acid from your stomach leaking up into your gullet (oesophagus), which leads to heartburn, that is, a burning sensation in your chest. 

Occasional heartburn, for example, caused by eating a very large, fatty meal, is very common and can last several minutes or hours. This can cause a cough if the stomach acid passes all the way up your gullet and droplets escape through the sphincter at the top of your gullet into your larynx (voice box) or airways. 

If you have GORD, you will experience heartburn regularly and, therefore, may have a persistent cough. If you experience mild heartburn at least twice a week or severe heartburn at least once a week, you may have GORD. 

6. Cough hypersensitivity syndrome

Cough hypersensitivity syndrome refers to a chronic cough where no underlying cause can be found. Bouts of cough happen in response to stimuli that wouldn’t ordinarily irritate your respiratory tract eg cold weather, steam, strong smells, laughing and talking. This is because your cough reflex has become too sensitive. 

This is more common in women, those aged over 40 and those who are overweight or obese. 

When to seek help

If you have a new cough with no obvious reason and it lasts three weeks or longer, it is important to see your GP. You should also urgently see your GP if your cough occurs alongside chest pain, a loss of appetite, coughing up blood, and/or unintentional weight loss. 

After an assessment and taking your medical history, your GP may refer you for a chest X-ray and blood tests to rule out more serious health conditions, such as lung cancer. In some cases, a CT scan and/or lung function tests may also be needed to identify the underlying cause.

Treating your cough will focus on treating the underlying cause identified. 

Lung cancer and coughing

It is important to note that lung cancer is rarely the cause of a cough. 
A cough caused by lung cancer can be dry or wet. Lung cancer occasionally also causes blood to be coughed up. 
Coughing up blood is an important warning sign of lung cancer, particularly if you’re a current or previous smoker. You should see your GP urgently and they will refer you for a chest X-ray.