What’s causing your cough?

We’ve all been through the irritation of a tickly cough that keeps us awake at night. It may not seem like it, but your cough reflex is there to protect you – it’s an automatic reaction to remove nasty stuff from your airways.

The bad stuff includes smoke or chemicals that irritate the lining of the tubes in your lungs, or mucus and germs as a result of infection.

A viral infection is the most common cause of cough in the short term (under three weeks). Flu and Covid-19 are both viruses that can cause serious infection – but a host of other viruses can give rise to symptoms of the common cold. You’ll often have a combination of a blocked, stuffy or runny nose; mild fever; and a tickly cough that may get worse when you lie flat.

Lower respiratory infections can be caused by viruses, bacteria or (less often) fungal infections. They include acute bronchitis – inflammation of your large airways – and pneumonia, infection deep in the lungs.

You’ll usually be sicker than with a cold, having a high fever, chesty cough, wheezing, shortness of breath and sometimes coughing up blood.

If you have asthma, there are triggers for worsening symptoms – cold weather, viral infections, pollution, allergies and more. Along with a cough, you may well experience shortness of breath and wheezing.

It’s important to take your inhalers regularly, and to have an asthma action plan which tells you when to increase your medication and when to seek medical help.

A cough for three to eight weeks is called a subacute cough. Sometimes, a viral infection that has cleared up leaves your airways inflamed and irritated.

While you may feel better in yourself – for instance, you’re unlikely to have a fever and may feel less tired and achy than you did – you may be left with an irritating, dry cough that’s worse if you exert yourself or lie flat.

Occasionally, a subacute cough can be caused by a whooping cough infection. In young children, this can lead to severe shortness of