The Tweed Hospital Emergency Department is seeing an 8% yearly increase in patients, which is three times the state average.
The ED has efficiently met the state's benchmarks for the treatment times, but according to the director, Dr Robert Davies, this achievement is unsustainable and strains other departments in the hospital.
"On current presentation numbers, 47,000 for the year, we should have over 32 spaces. We have 18," Dr Davies said.
"When an emergency department gets full and there are no spaces to treat patients, then care can be compromised," he said.
The impact is spread across all patients, he said.
"Blood tests may get delayed or medications given late.
"Patients may be slower to get to the operating theatre.
"Ambulances get held up in ED and 000 calls take longer to respond to.
"In another two years at this rate of growth we will be overwhelmed by presentations," Dr Davies said.
"We just don't have a facility to cope with those numbers."
More acute treatment and isolation wards for patients with infectious diseases are urgently needed.
"The Tweed senior medical staff are very concerned that we will be beyond crisis point before any infrastructure is built."