17833 Spirometry

Overview

Spirometry (say 'spy-ROM-uh-tree') is a simple breathing test. It measures how much air your lungs can hold and how fast you can blow it out. You breathe in deeply, then blow out as hard and as long as you can into a tube attached to a small machine called a spirometer. The machine turns your breath into a graph and numbers. Your doctor uses these to see how well your lungs are working and to help work out why you may be short of breath or coughing. Spirometry is a test, not a treatment and not a diagnosis on its own. It gives clues that your healthcare team puts together with your symptoms and history.

Very common. Spirometry is one of the most widely used lung tests in the world. It is done in GP surgeries, hospitals and clinics, and it is often the first breathing test someone has when they report a cough or breathlessness.

It can be done at almost any age, but children usually need to be around 5 to 7 years old before they can follow the instructions. It is used for people with asthma, people with smoker's lung disease (COPD), people who smoke or used to smoke, people with a cough that will not go away, people exposed to dust or fumes at work, and people who need a lung check before an operation. Anyone with a breathing worry may be offered one.

Symptoms

Common symptoms

• Spirometry itself does not cause symptoms. It is done to look into symptoms such as these:
• A cough that lasts more than a few weeks, or a cough that keeps coming back
• Shortness of breath when walking, climbing stairs or hurrying
• Wheezing (a whistling sound when you breathe)
• Tightness in the chest
• Coughing up mucus (phlegm) most days
• Chest infections that keep returning
• Breathlessness that wakes you at night or stops you exercising

Symptoms in children

• Children may be offered spirometry if they wheeze, cough a lot, or have asthma that is hard to control.
• It usually works from about 5 to 7 years old, once a child can follow simple instructions and blow hard.
• A nurse or technician will often practise with the child first using a fun game or a pretend birthday candle.
• If a child cannot manage it, other tests or a trial of treatment may be used instead. This is normal and not a failure.

Symptoms in older adults

• Older adults may need a few extra tries, and that is completely fine.
• The test can be done sitting down if standing is difficult.
• Tiredness, a dry mouth, arthritis in the hands or a recent fall can all make it harder, so tell the technician so they can help.
• Results are always read with your age in mind, so the numbers are interpreted for you rather than compared with a young person's.

Causes

Main causes

• Spirometry is done to look for the cause of breathing symptoms. The most common reasons it is requested are:
• Asthma: airways that become inflamed and narrow, often in flare-ups, and usually at least partly reversible with treatment
• COPD (chronic obstructive pulmonary disease), sometimes called smoker's lung: lasting damage that narrows the airways, most often from smoking
• Other lung conditions, such as scarring of the lung, bronchiectasis (widened, mucus-filled airways) or damage from work dusts
• Checking how well a known lung condition is controlled, and whether treatment is working
• A lung check before an operation or before starting certain treatments
• Health surveillance for people whose jobs expose them to dust, fumes or other lung irritants
• Sometimes to see whether breathing difficulty is coming from the lungs or from something else, such as the heart or being very unfit

Risk factors

• These are risk factors for lung problems that spirometry helps to find, not risk factors for having the test:
• Smoking, or having smoked in the past
• Growing up in a smoky home or with heavy air pollution
• Working with dust, asbestos, silica, coal, fumes, or in farming or welding
• A family history of asthma, COPD, cystic fibrosis or other lung disease
• Being born prematurely, or having chest infections in early childhood
• Allergies, eczema or hay fever, which often sit alongside asthma
• Being very overweight, which makes breathlessness more likely
• Long-term exposure to mould, damp or poor housing

When to see a doctor

See a doctor urgently if:

• Breathlessness that has got noticeably worse in the last day or two
• Chest pain with breathlessness
• A fever with a cough that is bringing up a lot of mucus
• Coughing up blood, even a small amount
• Feeling faint, very sleepy or confused alongside breathing trouble

Book a routine appointment if:

• A cough that has lasted more than three weeks
• Breathlessness that is new, or that stops you doing things you used to do
• Wheezing or a whistling chest
• Chest infections that keep coming back
• You smoke or vape and want advice about your lungs
• Your work exposes you to dust or fumes and you are worried about your breathing
• You have asthma or COPD and want to know how well it is controlled
• You have been told you need spirometry and are unsure what it involves

Diagnosis

Spirometry is itself the test, so there is nothing to 'diagnose' about the test. Here is what happens. You sit up, put a clip gently on your nose (to make sure all the air goes through your mouth) and seal your lips around a clean mouthpiece. The technician asks you to breathe in fully, then blast out as hard and as long as you can, until your lungs feel empty. You will usually do this at least three times so the best attempt can be used. Sometimes you will be given a medicine to breathe in that opens the airways, and the test is repeated 10 to 15 minutes later. This is called a reversibility test and helps show whether your airways loosen up. Nothing goes inside your body, nothing is injected, and the mouthpiece is new or thoroughly cleaned for each person.

Tests that may be done

• Spirometry: the main breathing test itself
• Bronchodilator reversibility: spirometry repeated after breathing in an airway-opening medicine
• Peak flow readings: short blows into a small hand-held device, often done at home over a few weeks
• A breathing test for airway inflammation, where you breathe gently into a machine (sometimes called FeNO)
• Pulse oximetry: a small clip on your finger that checks the oxygen level in your blood
• Chest X-ray or CT scan if your clinician needs to look at the lung structure
• Blood tests, for example to check for allergy or other causes of breathlessness
• More detailed lung function tests in a hospital lab, such as lung volumes or gas transfer, if the first results need following up
• A six-minute walk test or exercise test in some cases

What to expect at your appointment

The test is not painful, but blowing out hard can feel strange. You may cough, feel a bit dizzy or light-headed for a few seconds, or feel tired afterwards. This passes quickly and you can sit and rest. The technician will coach you: 'big breath in, now blast it out'. If you do not get it right first time, do not worry; it often takes a few goes. You should get the results either on the day or at a follow-up appointment. Ask for them to be explained in plain words, and ask what happens next.

Treatment

Spirometry is not a treatment. It is a test that helps your healthcare team choose the right treatment for you and check whether it is working. Once your results are known, your clinician will talk with you about what they mean and what options make sense. Many lung conditions are well controlled with the right plan, and spirometry is one of the tools that helps get that plan right.

Self-care at home

• Before the test: wear loose, comfortable clothing so you can breathe deeply.
• Do not smoke for at least several hours before the test, and ideally not at all. Smoking changes the results.
• Avoid a very heavy meal just before, and avoid vigorous exercise for about 30 minutes beforehand.
• Take your usual medicines as normal unless your clinician tells you otherwise. Never stop an inhaler for a test without checking first.
• Bring a list of all your medicines, including inhalers, tablets and anything you buy over the counter.
• Tell the technician if you have had recent chest or eye surgery, a collapsed lung, or if blowing hard is difficult for any reason.
• After the test: rest for a minute, drink some water, and you can go about your day as normal.

Medical treatments

Treatment depends on what the test shows, and your clinician will explain your options. In general terms, treatment for lung conditions may include inhaled medicines that open the airways or reduce inflammation, tablets, a course of steroid medicine for a flare-up, a structured breathing and exercise programme (sometimes called pulmonary rehabilitation), oxygen for some people with low oxygen levels, and support to stop smoking. Some people are taught breathing exercises or how to clear mucus from their chest. You should always discuss any medicine, and any change to it, with your own doctor, nurse or pharmacist. Do not start, stop or change treatment based on test results alone without talking it through.

When is surgery considered?

Surgery is not part of having spirometry. However, spirometry is sometimes done before an operation to check that your lungs are strong enough for surgery and anaesthetic. In a small number of people with severe lung disease, specialist teams may discuss procedures such as lung volume reduction or transplant assessment. These are decisions made with a specialist team, not from a spirometry result alone.

Living with this condition

There is nothing to recover from after spirometry. You can drive, work and exercise straight afterwards. If you felt light-headed, sit for a few minutes and have a drink first. Your results may lead to a new plan: a new inhaler technique, a follow-up appointment, or simply reassurance. Keep a note of your questions so you can ask them at your next visit.

Lifestyle tips

• If you smoke, stopping is the single biggest thing you can do for your lungs. Ask your GP, nurse or pharmacist for support; there are several ways to get help and you do not have to do it alone.
• Try to avoid breathing in dust, fumes, strong cleaning products or smoke, including second-hand smoke.
• Stay active. Regular walking, cycling or swimming helps your heart and lungs work better.
• Keep your home well ventilated and deal with damp and mould.
• Use any inhaler exactly as shown to you, and ask for your technique to be checked at review appointments.
• Keep up with your routine reviews, even when you feel well.
• Note down your breathlessness or cough on a simple scale so you can see changes over time.

Diet and exercise

There is no special diet for spirometry. A balanced diet and a healthy weight help you breathe more comfortably, because carrying extra weight makes the heart and lungs work harder. If you get breathless when eating, try smaller meals more often and rest before you eat. For exercise, start gently and build up. Walking, swimming, cycling and gentle strength work all help. If you have a lung condition, a supervised exercise and education programme can make a real difference to breathlessness and confidence. Ask your clinician whether one is available to you.

Mental health and emotional wellbeing

It is very normal to feel anxious before a breathing test or while waiting for results. Breathlessness itself can be frightening, and worry can make you breathe faster, which can feel worse. Tell your clinician if you feel anxious; they can slow things down and explain each step. If worry, low mood or panic is affecting your sleep, work or daily life, please talk to your doctor or nurse. You deserve support, and it is a normal part of looking after a lung condition. If you ever feel you cannot keep yourself safe, contact your local emergency number or a crisis line in your country straight away, and reach out to someone you trust.

Prevention

You cannot prevent needing a test, but you can protect your lungs so that breathing problems are less likely. Not smoking, or stopping if you do, is the most important step. Avoid breathing in dust and fumes at home and at work, use the right protective equipment if your job exposes you, keep your home free of damp and mould, and stay physically active. Catching problems early, which is exactly what spirometry helps with, means treatment can start sooner.

Vaccines

Vaccination helps prevent chest infections that can damage lungs or cause flare-ups. Ask your doctor or pharmacist whether you are due for flu, COVID-19 or pneumococcal (a bacteria that causes pneumonia) vaccination. This is especially important if you have a long-term lung condition, are older, or are pregnant.

Screening programmes

Spirometry is not currently offered as a routine screening test to everyone. It is used when you have symptoms, when you have risk factors such as a smoking history or workplace exposure, or as part of a review of a known lung condition. Some countries and regions run targeted lung health checks for people at higher risk. Ask your GP or local health service whether any programme applies to you.

Complications

If left untreated

• Spirometry itself rarely causes problems. Some people feel dizzy, cough, or briefly faint; this settles quickly and the technician will look after you.
• The bigger issue is what happens if breathing problems are not looked into. Untreated asthma or COPD can lead to more frequent flare-ups, more chest infections, and a slow decline in how far you can walk or how well you sleep.
• Breathlessness that is not assessed can also hide other treatable conditions, such as heart problems or anaemia.
• Getting a clear answer sooner means the right treatment can start sooner, which usually means fewer symptoms and a better quality of life.

Long-term outlook

The outlook is generally good. Most people who have spirometry get a clear answer and a plan. Asthma and COPD can be well controlled for many years with the right treatment, breathing techniques and lifestyle changes. Spirometry gives you and your clinician solid information to work from, and knowing what is going on is usually a relief. Keep your follow-up appointments, ask questions, and tell your team if something is not working for you.

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