The chairman of BMA Scotland’s GP committee said the pressure caused by coronavirus could cause the system to “overheat”.
Dr Andrew Buist said expectations about what the NHS could provide would have to change until a vaccine for Covid-19 was found.
In an interview with The Herald newspaper, he said: “We are heading into the most difficult period the NHS has experienced since it started in 1948.
“I’m quite worried about the current situation and what may come next. We are facing a very difficult four of five months, until we have a Covid vaccine.
“The whole system is going to overheat and I’ve said this to (Health Secretary) Jeane Freeman. We need to have a conversation with the public about their expectations.”
Resources should be prioritised for patients with “significant problems”, he said, until a vaccine for Covid-19 was found.
Dr Buist continued: “It is crucial to keep GP practices as Covid-free as possible, which is why we believe the top priority at this time should be the development of a dedicated, community-enhanced Covid pathway building on the success of the existing Covid-19 community pathways, that will safely divert respiratory activity away from A&E and general practice.
“More consideration needs to be given to the urgent care proposal set out by the Scottish Government, and it should at least be piloted and evaluated in the first instance, particularly given the extra pressure it may put on primary care.”
A Scottish Government spokeswoman said: “Our NHS remains open with public health measures in place to protect staff and patients.
“It is as important as ever to seek advice from NHS Inform whenever you feel unwell, or speak with your GP at the earliest possible time if you have serious health concerns or symptoms.
“Emergency departments are available for people requiring medical attention in emergencies.
“As we have repeated throughout the pandemic, everyone should continue to attend regular check-ups and appointments when invited to do so.
“Everyone who is registered with a GP practice in Scotland, or who lives in Scotland, is also encouraged to use their local pharmacy if they have a minor illness or common condition.”