Diagnosing asthma

There are several different signs that you may have asthma. Many of the symptoms are similar to those of other conditions, so it’s vital that you see your GP.

Asthma often develops in childhood, although some people get asthma for the first time as adults. Even then, there are often signs of asthma in earlier life, which may not have been diagnosed (typically people report a history of "colds that always went to my chest").

Asthma symptoms can be similar to symptoms for other lung diseases, such as COPD (chronic obstructive pulmonary disease) or even heart disease. So getting proper medical advice is important.

If it looks likely that you have asthma, your doctor will ask you specific questions to find out if your work is causing it.

Asthma can be made worse by certain occupations, for example, if you work with paint sprays, sterilising chemicals or in a dusty environment.

The symptoms of asthma

You may have shortness of breath, a cough or wheeze that comes and goes. It could be worse in the morning when you wake up, and at night. Factors such as exercise, the cold, dust, pets or your emotions may trigger your asthma symptoms.

According to GP Dr Kevin Gruffydd-Jones, asthma is different from other conditions because it's episodic, i.e. it comes and goes, and people with asthma are otherwise generally well.

Dr Gruffyd-Jones said: "People with asthma don't have weight loss or anything like that. In older people, the symptoms may mean that they have COPD or other respiratory illness, or possibly heart problems.

"We also check if there's a strong family history of asthma, or whether the patient has atopic eczema or hay fever. This could make a diagnosis of asthma more likely." 

How is asthma diagnosed?

Clues that it's asthma

  • Shortness of breath 
  • Cough
  • Wheeze
  • Symptoms can be brought on by triggers, such as cold weather, exercise, dust and pet hair 
  • Symptoms occur even when you don't have a cold 

Doctors diagnose asthma mainly by asking you questions about your health, and possibly doing certain tests. As a general guide:

  • you'll be asked if there's a family history of asthma or allergies
  • you'll be asked if there any other signs of chest disease or heart disease
  • you'll have a lung function test using a peak flow meter (a device that measures how hard and quickly you blow air out of your lungs to see how well they're working)
  • you may be given a drug to open your airways to measure your lung capacity

For more detailed information on how asthma is diagnosed, read the information in our NHS guide to living with asthma.

Pre-school children

Pre-school children can't do objective tests, so GPs check whether they have all the symptoms of childhood asthma. Are their symptoms worse at night or in the morning? Do they come and go? Do they appear more with certain triggers? Is there a strong family history of allergy?

According to Dr Gruffydd-Jones, if there's a good chance that your child has asthma (based on the questions above), your GP may give them a trial treatment to see if they get better. If they do, they'll continue the treatment.


Asthma is a chronic condition causing cough, wheezing and breathlessness. Professor Peter Barnes from Imperial College, London, explains what he would want to know if he was diagnosed with asthma.

Media last reviewed: 21/10/2013

Next review due: 21/10/2015

Page last reviewed: 13/02/2012

Next review due: 13/02/2014


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Advice on allergies such as eczema and food allergy, and what treatments are available on the NHS

Living with asthma

Information on diagnosing, treating and living with asthma, as well as what to do during an asthma attack