Here are some terms you may hear after being diagnosed with pulmonary fibrosis. Common pulmonary fibrosis terminology is listed in alphabetical order. We also have a simple glossary for lung function, as well as a general abbreviations list of commonly used terms in hospital clinic letters.


Alveolus, alveoli

Tiny air sacs in your lungs where oxygen leaves and enters the bloodstream.

Anti-fibrotic drugs

Drug treatments such as nintedanib and pirfenidone, which aim to slow down lung scarring and slow the rate at which the disease gets worse.

Autoimmune disease

Diseases such as rheumatoid arthritis and scleroderma, where your own immune system attacks your body and makes it inflamed. These can cause pulmonary fibrosis.



One of the most common symptoms of pulmonary fibrosis. People who are breathless may also be described as hungry for air or short of breath.



Where tissue becomes damaged and scarred, making it thicken and become stiffer. Pulmonary fibrosis (scarring in your lungs) makes it harder for you to breathe.

Forced vital capacity (FVC)

The total amount of air you breathe out during a breathing test. The lower your FVC, the more serious the disease is.


Hypersensitivity pneumonitis

Pulmonary fibrosis caused by an immune reaction to dusts breathed into the lungs.



Of unknown cause

Idiopathic pulmonary fibrosis (IPF)

Pulmonary fibrosis of unknown cause. The most common type of pulmonary fibrosis.

Interstitial lung disease (ILD)

A group of diseases where the lungs are either inflamed or have scarring. Pulmonary fibrosis is a type of ILD. You may visit an ILD unit in a hospital.

ILD consultant

A senior doctor in a hospital who specialises in interstitial lung disease (ILD), such as pulmonary fibrosis.

ILD nurse

A nurse who specialises in interstitial lung disease (ILD). You may see an ILD nurse as a member of your medical team.



One of the most common symptoms of pulmonary fibrosis. Lethargy is also known as tiredness or fatigue.


Occupational therapy

A type of therapy to help you live with pulmonary fibrosis symptoms more easily. You might see an occupational therapist to help you manage exercise and everyday activities.


Palliative care

Care that aims to improve a patient’s quality of life. You can have palliative care at any stage of a disease, not just at the end of your life.


Getting worse over time. Idiopathic pulmonary fibrosis (IPF) is a progressive disease.


Relating to the lung

Pulmonary fibrosis

Diseases where there is lung scarring. Idiopathic pulmonary fibrosis (IPF) is the most common type.

Pulmonary hypertension

A lung condition where there is increased blood pressure within the arteries of the lungs. Pulmonary hypertension can be a complication of pulmonary fibrosis.


An American term for a doctor who specialises in all lung problems. Equivalent to a Respiratory consultant in the UK.


Respiratory consultant

A senior doctor who specialises in diseases affecting breathing.



A disease where groups of inflamed cells form small lumps (granulomas) in the lungs or other tissues. Sometimes it leads to pulmonary fibrosis.


Where tissue becomes damaged, making it thicken and become stiffer. Typically seen when a wound is healing. Scarring is often known as fibrosis.


TLco and DLco

One of the lung function tests, also known as ‘gas transfer’, indicating how well the alveoli can transfer gases (such as oxygen) from the air into the blood.

Lung (pulmonary) function tests

Lung function tests are used to assess severity of pulmonary fibrosis, changes over time, suitability for some treatments, and need for lung transplantation.

Lung function tests results provide information about airflow, lung size, and gas exchange.

Results are commonly presented as a percentage or ‘percent predicted’ figure which has been adjusted to your height, age and gender according to approved standard tables.


Spirometry is the most commonly performed and simplest lung function test. It involves breathing out through a tube, and it measures airflow over time.

Forced Expiratory Volume in 1 second (FEV1) -

The volume of air expelled in the first second of a forced expiration (breath out) following a full inspiration (breath in).

Forced Vital Capacity (FVC)

The greatest volume of air which can be exhaled from the lungs during a forced and complete expiration (breath out) from a position of full inspiration (breath in).

FEV1 / FVC  

The ratio of FEV1 to FVC.

Peak Expiratory Flow Rate (PEFR)

The highest flow rate that can be achieved during a forced expiration from a full inspiration.

Lung volumes

Total Lung Capacity (TLC)

The total volume of air in the lungs at full inspiration.

Tidal Volume (TV)

The volume of air breathed in and out with each resting breath e.g. normal quiet breathing.

Functional Residual Capacity (FRC)

The volume of air remaining in the lungs at the end of a tidal (normal/quiet) breath.

Residual Volume (RV)

The volume of air remaining in the lungs after a maximum expiration.

Alveolar Volume (VA)

This estimates the lung volume available for gas exchange.

Gas transfer

A gas transfer test tells us how efficient the lungs are at taking up oxygen from the air we breathe.  The exchange of gases occurs across the alveolar-capillary membranes in the lungs (alveoli are the tiny air sacs in the lungs and capillaries are the small blood vessels surrounding them). The main gases involved are oxygen (O2) and carbon dioxide (CO2).

Transfer Factor of the Lung for Carbon Monoxide (TLcoor DLco)

This shows how efficiently the lungs can transfer gas (oxygen) from the air to the blood. The test involves breathing in a low concentration of carbon monoxide (CO).

Transfer Coefficient of the Lung for Carbon Monoxide (Kco)

The TLco adjusted for alveolar volume (VA).

Guide to PF abbreviations

You can also download our helpful guide on abbreviations related to pulmonary fibrosis:

Information provided by Action for Pulmonary Fibrosis (APF) is not a substitute for professional medical advice. It’s intended as general information only. APF is not responsible for any errors or omissions or for any loss or damage suffered by users resulting from the information published on

Further information for carers:

Your essential caring guide (PDF)
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