NOT A DIAGNOSIS: But workplace stress can be used on a medical certificate.

A doctor's use of the term "workplace stress" on a medical certificate has angered an employment group, but is being defended by the medical association.

Employers and Manufacturers Association (EMA) workplace safety manager Paul Jarvie said the group was not happy that workplace stress was used as a medical diagnosis in a case before the Employment Relations Authority (ERA) last week.

In the case, the authority found the applicant was unjustifiably dismissed by her employer who was ordered to pay $10,000 in compensation.

The authority ruled that the employer failed to provide a safe working environment for the employee who suffered stress, leading to ill health and her resignation.

Before resigning, the employee had visited a doctor who diagnosed her with workplace stress and referred her to hospital where she was admitted for tests.

In 2004, a Labour Department paper said workplace stress was not a medical condition in its own right.

In 2013, the New Zealand Medical Council issued its own guidelines on medical certificates saying general practitioners should refer to the Ministry of Business, Innovation and Employment's (MBIE) guidance of patients complaining of work-related 'stress' problems.

Jarvie said the medical profession needs to be mindful of its legal obligations when issuing medical certificates.

"Workplace stress is not recognised as a medical condition. It's a symptom, not a diagnosis."

GPs, the ERA and Employment Court need to apply rigour in their use of such terms, he said.

"Illnesses such as hypertension, high blood pressure, depression and other mental disorders are definitively medical conditions and recognised as such internationally. Stress is not."

However, the New Zealand Medical Association's General Practitioner Council chairwoman Dr Kate Baddock said while workplace stress was not a diagnosis, it was not inappropriate for the doctor to have admitted the patient to hospital to have her work-related stress investigated.

"Without talking to the doctor who did it you don't know what their intention was by using the term," Baddock said.

"Workplace stress" could also be used as a term by a doctor to determine whether an employee was entitled to counselling paid for by their employer to address work-related stress, she said.

MBIE's website says because there is no legislative definition of stress, case law examples are often used in understanding the question of what constitutes workplace stress.

If an employer fails to adequately address workplace stress, they could face a claim in the District Court for a breach of obligations under the Health and Safety in Employment Act 1992, the website said.

Dundas Street Employment Lawyers partner Susan Hornsby-Geluk said it was "sloppy" work from the GP who issued the medical certificate which was referred to in the ERA case last week.

"There could potentially be grounds for a complaint by the employer to the medical council," Hornsby-Geluk said.

Employees should be able to rely on doctors to be provided a medically sound diagnosis, she said.