East London GP Dr Tom Margham, who has an interest in musculoskeletal medicine, said the failure to follow up and code symptoms such as knee pain as osteoarthritis is denying patients a full diagnosis.
It may mean co-morbidities such as depression, which is prevalent in patients with osteoarthritis, go undetected.
A report published last week by Arthritis Research UK revealed how GPs conduct 100,000 consultations for musculoskeletal conditions every day.
Between 1990 and 2010, disability due to osteoarthritis in the UK increased by 16%, a trend which is expected to continue.
Dr Margham, primary care lead for the charity, said a reluctance to code pain in parts of the body as arthritic disease without further tests had held back diagnosis rates.
Practices need to follow up patients with 'holding' codes for joint pain, some of whom may have a musculoskeletal condition, he said.
'Sometimes the code doesn't get updated. A patient doesn't need an X-ray [to be diagnosed with] osteoarthritis. But GPs are often reluctant unless they definitely know there's a diagnosis to code it as such.'
He said primary care experts support efforts to make a positive diagnosis and code this in the patient's record. 'For one, you will understand the disease burden in your practice. But you also can access guidelines more effectively, and understand the process for managing patients.'
Patients need a full diagnosis so they can access educational material on how to manage the condition, he said.
'Because we know levels of depression in people with chronic osteoarthritis are so high, those people might be at more risk. It helps you plan your services, and generally understand the need in the population,' he said.
Dr Margham added: 'The burden of disease is just going to get bigger and bigger over time. It's an important disease now, and will become even more so.'
Arthritis Research UK's report called for GPs to be alert to osteoarthritis in people with conditions such as heart or lung disease or diabetes, and routinely ask patients whether they are experiencing musculoskeletal pain.
