Chronic obstructive pulmonary disease (COPD) is the umbrella term for a group of conditions in which patients have difficulty breathing. This is due to obstruction of the flow of air through the respiratory system, which happens when the airways become inflamed, damaged and narrowed, usually – but not always – because of long-term exposure to harmful substances such as cigarette smoke.

COPD is progressive, which means that it worsens over time, and although it can often be kept under control, it isn’t curable because the damage to the delicate inside of the lungs is irreversible.

The two main conditions that fall under the term COPD are:

• Emphysema, in which the alveoli become damaged

• Chronic bronchitis, in which the airways are inflamed, causing mucus to be produced.

These give rise to symptoms such as a chronic productive cough; breathlessness, particularly upon exertion; persistent wheezing; and frequent chest infections. There may also be issues such as tiredness and weight loss – due to the effort needed to breathe and deal with wheezing and coughing – and occasionally swollen ankles and chest pain. Sometimes COPD symptoms suddenly worsen, with the patient experiencing more breathlessness, coughing and phlegm than normal. This is known as an acute exacerbation.

In the UK, more than three million people are believed to have COPD, though the condition is undiagnosed in around two thirds of these individuals. The reason for this is that many people don’t seek help because symptoms start and worsen slowly, and they put it all down to simply getting older. There are several risk factors for developing COPD: ageing and being male are two, but the most significant is being a smoker.