Coughing 101: recognising different types of coughs...

Some people with long-term conditions, such as chronic bronchitis or bronchiectasis, have to cough frequently. This is because the lung’s cilia – tiny hair-like structures that move mucus, debris and germs – no longer work to clear the lungs. 

A wet or 'productive' cough means coughing up a lot of mucus. A cough can also be dry or 'unproductive'. This happens when the cough receptors in the airways, throat and upper oesophagus have become overly sensitised, triggering a cough even when there’s no mucus to clear. 

Causes of chronic coughs are:

• post-nasal drip (where mucus drips from the back of the nose into the throat),
• asthma,
• acid reflux from the stomach.

Coughs can also persist long after a viral or bacterial infection. In children with colds, one systematic review found it took 25 days for more than 90% to be free of their cough. 

Contagious coughs are:

When a cough persists, a common concern is whether a secondary bacterial infection has followed the first viral infection, requiring antibiotics. 

Simply coughing up yellow or green phlegm is not enough to tell. 

To diagnose a serious chest infection, your doctor will consider the whole picture of your symptoms. For example, whether you also have shortness of breath, worsening fever or your lungs make abnormal sounds through a stethoscope. 

The possibility that you have undiagnosed asthma or allergies should also be considered. 

What treats a persistent cough? 

People with a persistent cough who are otherwise healthy may request and be prescribed antibiotics. But these rarely shorten how long your cough lasts, as irritation – not infection – is the primary cause of cough. 

The most effective treatments for shifting sticky mucus from the airways are simple ones: saline nose sprays and washes, steam inhalation and medicated sore throat sprays. 

Honey has also been shown to reduce throat irritation and the need to cough. 

The effectiveness of cough syrup is less clear. As these mixtures have potential side effects, they should be used with care. 

A cough indicates something more serious when you:

• cough up blood,
• produce a lot of phlegm
• are very short of breath, especially when resting or at night,
• have difficulty swallowing,
• lose weight or have a fever,
• have recurring pneumonia,
• are a smoker older than 45, with a new or changed cough