Doctors, nurses and ambulance officers have come together in Adelaide to demand more action from the government to solve hospital overcrowding.

Doctors, nurses and ambulance officers have come together in Adelaide to demand swift action from the state government to end overcrowding in public hospitals, particularly emergency departments.

Ambulance officers will consider not processing bills for transport and nurses may limit elective surgery from Monday if the government doesn't act by Friday to provide more beds.

Hospital doctors say they won't stand in the way of industrial action and will wage their own campaign to convince the government to respond.

The three groups want 50 beds opened at the recently mothballed Repatriation Hospital to take sub-acute patients as a first step to ease the pressure.

Ambulance Employees Association state secretary Phil Palmer says the situation has reached crisis point, putting lives at risk.

"What we want is for the government to open more beds," Mr Palmer told reporters on Wednesday.

"Whatever it costs, it needs to be done because South Australians are at risk.

"The whole hospital system is in a mess."

Australian Nursing and Midwifery state secretary Elizabeth Dabars said nurses were in deep distress that their patients were suffering.

"It is only a matter of time before a tragedy strikes," she said.

Salaried Medical Officers Association senior industrial officer Bernadette Mulholland said if issues across the hospital system were not addressed it would lead to a "spiralling of this crisis".

"We need it to stop. We need the leadership to step up....so that we can have a good health system for our patients and our community who need this on a daily basis," she said.

Health Minister Stephan Wade said 20 beds would be made available in private hospitals, on top of 30 previously provided in country hospitals to ease the situation in the metropolitan area.

"We'll continue to look at medium to long-term strategies but it's very important that we provide the relief now so that our doctors, nurses and paramedics get the support that they need," he said.

Mr Wade said it would take "weeks if not months" to activate the beds at the Repatriation Hospital, but that was actively being considered.

The minister will meet with the three unions again on Friday.