This comes after the results of a survey by the charity revealed that 80 per cent of UK GPs find distinguishing between a diagnosis of asthma and COPD quite or very challenging.
The online survey of 776 GPs found that nearly a third - 32 per cent - of GPs who responded did not know how many patients in their practice had both COPD and asthma.
Additionally, one in 10 practices had no staff who could carry out or interpret spirometry tests.
Dame Helena Shovelton, chief executive of the British Lung Foundation, said: 'We are calling for everyone over 35 with an asthma or COPD diagnosis to be re-tested and for this to be made part of the GP contract next year.'
But Dr Kevin Gruffydd-Jones, a GP in Wiltshire and a member of the General Practice Airways Group (GPIAG), warned that it would not be practical to do mass re-testing of all patients with asthma and COPD.
'That would be around 8 per cent of patients in a practice. That is a huge number of patients to re-test,' he said.
'Instead, GPs should check that they have made the right diagnosis when patients present for their individual reviews.'
Patients who have poorly controlled asthma should be checked to ensure that they have asthma and not COPD, said Dr Gruffydd-Jones.
'It is very important to distinguish between the two conditions as the treatment regimens have fundamentally different aims.
'But it is difficult to make the distinction as the conditions have a wide range of overlapping symptoms. Some patients can also have both conditions.'
There is an urgent need for better training as well as access to spirometry, he said.
Somerset GP Dr Steve Holmes, former chairman of GPIAG, added that GPs should follow the available guidance from NICE and the British Thoracic Society to help them diagnose the conditions.
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