What tests will the GP do to diagnose COPD?

A General Practitioner (GP) uses a core breathing test along with a few supportive investigations to diagnose Chronic Obstructive Pulmonary Disease (COPD).¹²

Primary Diagnostic Test

• Spirometry: This is the essential, gold-standard test required to confirm a COPD diagnosis. You blow as hard and fast as you can into a tube connected to a small machine called a spirometer. It measures how much air you can breathe out in one second (FEV₁) and your total vital capacity (FVC).¹²³⁴
• Bronchodilator Reversibility Test: Often performed alongside spirometry, you take an inhaled medication to open your airways, wait a short period, and repeat the breathing test to see if the airflow obstruction improves or if it points more toward asthma.¹²

Supporting Tests & Investigations

Your GP may order additional tests to rule out other conditions (like asthma or heart failure) or to assess the severity of your symptoms:¹²

• Chest X-ray: To check for signs of trapped air (hyperinflation), a flattened diaphragm, or other lung conditions such as chest infections or lung cancer.¹²
• Blood Tests: To check your general health and rule out things like anaemia or polycythemia (high red blood cell count), or sometimes to test for alpha-1-antitrypsin deficiency (an inherited condition that can cause COPD).¹²
• Pulse Oximetry or Arterial Blood Gas (ABG): To measure the oxygen and carbon dioxide levels in your blood.¹²
• Peak Flow Test: Serial peak flow measurements may be used if there is uncertainty between COPD and asthma.¹²
• Chest CT Scan: May be considered if your symptoms are severe, don't match your lung function results, or if your GP needs a more detailed view of your lung tissue.¹²

To help tailor this information, tell me:

• What symptoms prompted you or someone else to visit the GP?
• Is there a history of smoking or exposure to lung irritants?

If a GP suspects Chronic Obstructive Pulmonary Disease (COPD), they will usually start with a thorough review of your symptoms, medical history, and exposure to risk factors (such as smoking or workplace dust/chemicals).¹²

To confirm the diagnosis and check your overall lung health, they will typically arrange or perform the following tests:

1. Spirometry (The Key Breathing Test)

• What it is: A simple, standard breathing test where you blow as hard and as fast as you can into a machine called a spirometer.
• What it measures: The volume of air you can breathe out in one second (FEV₁) and the total amount of air you can force out in a single breath (FVC).
• Why it matters: It is the primary test used to prove whether your airways are obstructed.¹

2. Chest X-Ray

• What it is: A quick imaging scan of your chest.
• Why it matters: It helps rule out other conditions that can cause similar symptoms, such as a chest infection, heart failure, or lung cancer.¹

3. Blood Tests

• What it is: A standard blood draw.
• Why it matters: It is used to check for things like anaemia (which can cause breathlessness) or to test for a rare genetic condition called alpha-1 antitrypsin deficiency, which can cause COPD in some people even if they have never smoked.¹

4. Pulse Oximetry

• What it is: A painless sensor clipped onto your finger.
• Why it matters: It measures the oxygen saturation level in your blood to see how well your lungs are oxygenating your body.¹

5. Body Mass Index (BMI) Calculation

• What it is: Measuring your height and weight.
• Why it matters: COPD can affect your weight and nutritional status; knowing your BMI helps the clinical team plan your long-term care and exercise rehabilitation.¹

Where to go for more details

You can read more about what to expect during these appointments via the NHS Guide to COPD Tests or through Asthma + Lung UK.¹²

Are you asking because you or someone you know is currently experiencing symptoms like breathlessness or a chronic cough, or are you preparing for an upcoming GP appointment?

If your GP suspects COPD (Chronic Obstructive Pulmonary Disease), they will usually arrange a few checks to see whether your lungs are working properly and rule out other conditions, such as asthma, a chest infection or heart problems.

The most important test for diagnosing COPD is called spirometry.

1. Spirometry (breathing test)

This is the main test used to confirm COPD.

• You take a deep breath in.
• You blow out as hard and as fast as possible into a mouthpiece.
• The machine measures how much air you can breathe out and how quickly.
• You may repeat the test several times.
• Sometimes you are given an inhaler and asked to repeat the test afterwards.

The GP looks at two measurements:

• FEV1: How much air you can force out in the first second.
• FVC: The total amount of air you can force out.

A low FEV1/FVC ratio after using a bronchodilator (usually below 0.7) can indicate COPD, when considered alongside your symptoms and medical history.

2. Chest X-ray

This checks for:

• Signs of lung damage or overinflation.
• Chest infections.
• Other possible causes of breathlessness.
• Any abnormalities that might need further investigation.

A chest X-ray alone cannot diagnose COPD.

3. Blood tests

The GP may arrange blood tests to:

• Check for anaemia, which can cause breathlessness.
• Check your red and white blood cell counts.
• Look for signs that might suggest other conditions.
• Occasionally check for an inherited condition called alpha-1 antitrypsin deficiency.

4. Oxygen level check

A small clip is placed on your finger to measure:

• Oxygen saturation (SpO2).
• Your pulse rate.

This is painless and takes seconds.

5. Other possible tests

Depending on your symptoms, you might also have:

• ECG: Checks your heart rhythm to rule out heart-related breathlessness.
• Peak flow: Measures how quickly you can breathe out and can help distinguish asthma.
• CT scan: Gives a more detailed picture of your lungs if needed.
• Sputum test: Checks for infection if you regularly cough up phlegm.

These aren't all needed for everyone. www.nhs.ukwww.nice.org.ukwww.asthmaandlung.org.ukwww.nhsinform.scot

What happens at your first GP appointment?

Usually, the GP will:

1. Ask about coughing, wheezing, breathlessness and phlegm.
2. Ask whether you smoke or have smoked in the past.
3. Listen to your chest.
4. Check your oxygen levels.
5. Arrange spirometry, a chest X-ray and blood tests if appropriate.

One important thing: COPD is not diagnosed just because you smoke, cough or get breathless. Spirometry is needed to confirm it.

Can I ask you something?

Are you asking because you've been experiencing symptoms yourself?

For example, do you have:

• Breathlessness when walking or climbing stairs?
• A persistent cough?
• Wheezing or a tight chest?
• Regular phlegm or mucus?
• Frequent chest infections?

If you tell me what symptoms you're experiencing and for how long, I can help explain whether they are typical of COPD or whether something else might be causing them.