Chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease is an umbrella term for a group of lung conditions characterised by persistent respiratory symptoms. It includes:

• Emphysema – where the alveoli (tiny air sacs) in the lungs’ airways become damaged over time and eventually rupture, creating larger pockets that trap air. This prevents oxygen from moving out of the lungs and through the bloodstream, making breathing increasingly difficult (British Lung Foundation, 2022a; National Institute for Health and Care Excellence (NICE), 2023; American Lung Association, 2024a).
• Chronic bronchitis – where the bronchi (airways) become inflamed and narrowed, causing coughing that often produces sputum, as well as chest pain, wheezing and shortness of breath (British Lung Foundation, 2022a; American Lung Association, 2024b).

Chronic bronchitis is defined as cough and sputum production for at least 3 months in each of 2 consecutive years. Chronic obstructive pulmonary disease is the preferred term for chronic obstructive airways disease (NICE, 2023).

The primary symptoms of chronic obstructive pulmonary disease are:

• persistent breathlessness that worsens on exertion (even when performing everyday activities)
• chronic cough
• wheeze
• frequent sputum production
• recurrent lower respiratory tract infections (British Lung Foundation, 2022a; NICE, 2023)

These symptoms might be present to a lesser or greater degree constantly, or they might improve for some time then worsen if the patient develops an infection, catches a cold, spends time in a smoky environment, or exerts themselves more than normal.
Patients might present with the other symptoms as their chronic obstructive pulmonary disease progresses, although it is important to consider other possible causes.

Other symptoms include:

• loss of appetite
• weight loss
• fatigue
• reduced exercise tolerance
• waking at night with breathlessness
• chest pain (a possible symptom of chronic obstructive pulmonary disease, but uncommon)
• haemoptysis (coughing up blood – a possible symptom of chronic obstructive pulmonary disease, but uncommon)
• ankle swelling (consider cor

The most common cause of chronic obstructive pulmonary disease is smoking tobacco, with around 90% of cases associated with cigarette smoke (NICE, 2023). Smoking pipes, cigars and marijuana also increases the risk of chronic obstructive pulmonary disease, and second-hand smoke – also known as passive smoking – is thought to contribute as well (NHS, 2023a; NICE, 2023).

Chronic obstructive pulmonary disease is most common in people over the age of 35 years, who smoke or have smoked in the past, or who had lung problems during childhood (British Lung Foundation, 2022a). Occupational exposure to some substances plays a role in some cases of chronic obstructive pulmonary disease. This happens in two ways:

1. Exposure to certain types of dust or fumes. The following can potentially cause chronic obstructive pulmonary disease if a person is exposed to high quantities over a long period:

• cadmium dust and fumes
• welding fumes
• silica dust

Chronic obstructive pulmonary disease might be suspected if a patient presents with several of the primary symptoms. On examination, the following signs may also be present:

• cyanosis (the skin and/or lips appearing blue)
• raised jugular venous pressure
• peripheral oedema (swelling, eg in the ankles)
• low weight and muscle wasting (cachexia)
• hyperinflation of the chest (a ‘barrel chest’ appearance) (Watson, 2017)
• laboured breathing, using the accessory muscles and/or pursed lips
• wheezing and/or cracking when listening to the chest (NICE, 2023)

A chest X-ray and blood tests may be useful to rule out other causes of the patient’s symptoms (British Lung Foundation, 2022c).

The patient’s breathlessness level can be graded 1 to 4 according to the Medical Research Council (MRC) dyspnoea scale, where a score of 1 means they are only troubled by breathlessness on extreme exertion, and a score of 4 means they are too breathless to leave the house or

If the patient currently smokes, the most important step they can take to reduce the severity of their symptoms and halt or slow the progression of their chronic obstructive pulmonary disease is to stop smoking. They should have smoking cessation support and treatment where required (NICE, 2019; NHS, 2023a). Other core aspects of managing the disease may also be used.