Respiratory glossary

We have created an A-Z of respiratory conditions that we care for at Barnet, Chase Farm and the Royal Free hospitals and some of the treatments we provide.


Asthma is a disease of the airways that results in attacks of breathlessness, as well as coughing and wheezing.


During a bronchoscopy the airways are inspected and sampled using a thin, flexible telescope.

Chest drain

A chest drain is a thin, flexible tube passed into the space between the lung and the chest wall, to treat a pleural effusion or pneumothorax.

Chronic obstructive pulmonary disease (COPD)

This is a disease of the lungs where the lungs become inflated, often as a result of tobacco smoke.

CT scan

A CT scan is a sophisticated type of x-ray which shows the structure of the lungs in detail.

EPIC service

This stands for ‘Early Presentation and Intervention’ in COPD. It is a new service we are developing for patients with COPD in which we provide direct advice to specialists with the aim of reducing hospital admissions.

Lung cancer

A cancer is a disease where the cells (building blocks) of the body grow and divide out of control. Cancers that start in the lung are called lung cancer, but sometimes the lungs may be affected by cancers that have started elsewhere and spread.

Lung fibrosis

Lung fibrosis is the general term for a number of different diseases which all result in excessive scarring of the lung. This often causes slowly worsening breathlessness and cough.

Lung function test

A lung function test helps us to decide what the cause of your symptoms may be and are performed in our modern, well-equipped laboratory. Some involve blowing into a machine, others involve breathing different gases. Some tests still involve measuring lung volumes by sitting in a box.

Non-invasive ventilation

Non-invasive ventilation is a machine to help the breathing muscles which works using a tight fitting nose or face mask.

Positron emission tomography (PET) scan

A PET scan is a sophisticated scan that helps us to decide whether a shadow we have seen on an x-ray or CT scan is likely to be cancer or not.

Pleural effusion

The condition where an excess amount of fluid builds up in the space between the lung and the chest wall, squashing the lung and causing breathlessness. There are lots of causes. It is usually treated with a chest drain.


A pleurodesis is a medical procedure in which the two membranes lining the lung and the chest wall are stuck together to stop a pleural effusion from coming back.


Pneumonia is an infection of the lung.


A pneumothorax happens when air has escaped from the lung into the space between the lung and the chest wall. It often causes chest pain and breathlessness and is treated with a chest drain.

Pulmonary embolism

Pulmonary embolism is development of a blood clot on the lung. These may cause breathlessness and chest pain, and usually start from a clot in the leg.

Pulmonary rehabilitation

An exercise and educational programme for people with lung diseases to enable them to manage their condition and optimise their exercise capacity.


A disease of unknown cause, that can affect any organ, but which often causes enlargement of glands within the chest.

Sleep apnoea

A condition in which the muscles at the back of the throat relax when asleep and briefly cause the airway to narrow or block. It often causes snoring, but also may result in daytime tiredness.

Tuberculosis (TB)

Tuberculosis is a specific lung infection that needs careful treatment to cure. Because it may be passed from person to person, it may be necessary to contact people who have been in contact with an infected patient.

VQ scan

A VQ scan is a specific scan using low dose radioactivity to help in the diagnosis of pulmonary embolism.