Chronic obstructive pulmonary disease (COPD) diagnosis

COPD is an umbrella term for a group of lung conditions that cause the airways to become narrowed, so those with it find it difficult to breathe air out of their lungs. There’s no cure for COPD but it can be treated so that symptoms can be managed. Important is COPD diagnosis.

Worldwide, around 300 million people have COPD. In Europe, around 5-10% of people have the condition, and in the UK around 1.2 million people are diagnosed with it – although it’s estimated that a further 1.8 million people might be unaware that they are living with COPD. This is partly because COPD develops slowly over years, so many people only start to recognise their symptoms in their 50s.

It’s estimated that around 70% of COPD cases remain undiagnosed, globally. At the same time, however, between three and six people out of 10 are thought to be wrongly diagnosed with COPD.

Conditions associated with COPD

Chronic bronchitis and emphysema are commonly associated with the disease, and can lead to COPD. Bronchitis causes the airways to become irritated and inflamed, and lead to people producing more mucus (also called sputum or phlegm) than they usually would. Emphysema occurs when the air sacs in the lungs are damaged – either weakened or ruptured. This can make larger air spaces and affect how much oxygen reaches the bloodstream.

When should I see my doctor?

The early signs of COPD are:

  • Increasing breathlessness
  • A chesty cough that produces phlegm and won’t go away
  • Wheezing
  • Frequent chest infections.

Your symptoms might worsen for a short period (called a flare-up), particularly in the winter.

If you’re experiencing these symptoms persistently, especially if you’re over 35 years old and you smoke or used to smoke, see your family doctor for medical advice. 

How is COPD diagnosed?

COPD is often wrongly diagnosed as there are other conditions and diseases with similar symptoms, such as Bronchiectasis and asthma.

Your doctor will ask you about your symptoms and how they affect your daily life:

  • Breathlessness – is it persistent, has it worsened over time, is it worse if you exercise, at night or at other times?
  • Cough – does it come and go, does it produce phlegm, do you also wheeze?
  • Chest infections – how often do you get these?
  • Family/childhood history – do any of your close relatives have respiratory problems, how was your health as a baby and child?
  • Risk factors or exposures – are you a smoker or ex-smoker, does your job or home life bring you into contact with airborne pollution (e.g. dusts, vapours, fumes, gases, chemicals, smoke from home cooking or heating fuels)?
  • Other symptoms – have you had any weight loss, ankle swelling, fatigue, chest pain or coughing up blood? These are less common, especially in mild COPD, and might point to a different diagnosis.

They’ll also listen to your chest with a stethoscope, take into account your age and calculate your body mass index (BMI) from your height and weight. If your doctor suspects you have COPD you will need some tests to confirm the diagnosis and rule out other possible causes.

What tests or investigations will I need?


This is a simple breathing test that measures how well your lungs are working. You’ll be asked to blow hard into a machine called a spirometer that measures the total volume of air that you can breathe out in one go, and also how quickly you can empty your lungs of air. The forced expiratory volume in 1 second (FEV1) will measure how much air you force out of your lungs, and use this to determine your results.

If you have COPD, your doctor will usually be able to diagnose it by assessing your signs and symptoms alongside your spirometry results. People with COPD have obstructed airways so they have a reduced FEV1. Doctors classify COPD into four stages – Mild, Moderate, Severe and Very Severe – depending on how reduced your FEV1 spirometry score is for your age.

If you reach 80% of your predicted FEV1 value, this will fall into mild COPD, between 50-79% would be considered moderate, between 30-49% would be severe and less than 30% would be very severe.

Chest X-ray

A chest X-ray doesn’t diagnose COPD, but it may reveal other lung problems that have similar symptoms, such as a chest infection or lung cancer.

Blood tests

These may be needed to rule out iron deficiency (anaemia), a high red blood cell concentration (polycythaemia) and a rare genetic disorder called alpha-1-antitrypsin deficiency.

Additional tests

Occasionally further tests are needed:

  • Sputum culture – to look for infection
  • Peak flow monitoring – to exclude asthma
  • Electrocardiography and serum natriuretic peptides or echocardiography – to check your heart
  • Chest CT scan – to look for other lung conditions such as bronchiectasis, fibrosis or lung cancer
  • Pulse oximetry – measures the oxygen level in your blood
  • Transfer factor for carbon monoxide
  • Spirometric reversibility testing – if the diagnosis is still uncertain.



NHS 2019. Overview. Chronic obstructive pulmonary disease (COPD).

NHS 2019. Bronchitis.

Mayo Clinic 2017. Emphysema. Symptoms & causes. 

Don D. Sin. Should COPD stand for “comorbidity-related obstructive pulmonary disease”? European Respiratory Journal 2015 46: 901-902,people%20each%20year%20%5B1%5D

Mayo Clinic 2020. Diagnosis & treatment.,walk%20test%2C%20and%20pulse%20oximetry

ERS White Book. Chapter 13. Chronic obstructive pulmonary disease.

BTS. nd. COPD.

NICE 2018. Information for the public. Chronic obstructive pulmonary disease: the care you should expect. NG115.

NHS 2019. Symptoms. Chronic obstructive pulmonary disease (COPD).

WebMD 2017. What are the four stages of chronic obstructive pulmonary disease (COPD) and the symptoms of each? 

Healthline 2020. FEV1 and COPD: How to Interpret Your Results. 

NHS. 2019. Diagnosis. Chronic obstructive pulmonary disease (COPD).

NICE 2018 (updated 2019). Chronic obstructive pulmonary disease in over 16s: diagnosis and management. NG115.

Diab N, Gershon AS, Sin DD, Tan WC, Bourbeau J, Boulet LP, Aaron SD. Underdiagnosis and Overdiagnosis of Chronic Obstructive Pulmonary Disease. Am J Respir Crit Care Med. 2018 Nov 1;198(9):1130-1139.