An acutely ill woman was forced to wait more than 24 hours in Blacktown Hospital's emergency department until she could have surgery, and administered morphine in a hallway, because no beds were available in the wards.

Kim Hilton, 38, is representative of a western Sydney population that has grown beyond the capacity of hospitals to meet the demand.

She attended the emergency department on August 3 experiencing excruciating abdominal pain, and a scan detected a gallstone.

But when she arrived at midday, the waiting room was groaning with patients and although she was admitted within an hour, she was sent back to the waiting room because no beds were free.

A winter surge of people with respiratory illnesses had resulted in 131 presentations to the emergency department that day, according to the hospital's administration – 17 more than would normally be expected.

For about seven hours, Mrs Hilton had to perch on the floor because there were not enough chairs.

"It was very chaotic in there," she Mrs Hilton said.

"You could tell that they were understaffed and they couldn't handle the patients. The 24 hours I was in the waiting room it was full pretty much the whole time. It was probably the most packed I've ever seen a waiting room."

Every few hours doctors ushered her into the hallway to administer morphine from a drip.

Once there was nowhere for her to sit to recover, so she sat on her bag until the wooziness had passed and she could walk back to the waiting room.

A nurse told her: "Just sit there a few minutes before you go back into the waiting room and if I hear a bang, I'll come running."

About 4am, doctors offered her a recliner chair in another room, which allowed her to rest until nurses returned her to the waiting room about 7am.

She was finally admitted to the surgical day ward about 1pm the day after she arrived.

Mt Druitt MP Edmond Atalla, who has complained to Health Minister Jillian Skinner about Mrs Hilton's experience, said the closure of wards at Mt Druitt Hospital was adding to the duress at Blacktown Hospital.

"How many patients that would normally have gone to Mt Druitt Hospital are now fronting up to the Blacktown Hospital and adding to that pressure and making the waiting times the worst in western Sydney?" Mr Atalla asked.

The median waiting time for patients to be admitted into a ward at Blacktown Hospital was eight hours and 30 minutes, compared with a state average of four hours and 50 minutes, according to the latest quarterly data released by the Bureau of Health Information.

Some patients waited nearly 30 hours to be admitted to a ward at Blacktown.

Blacktown Hospital general manager Sue-Anne Redmond said the day Mrs Hilton had arrived was particularly busy.

"The hospital deeply regrets that demand for beds exceeded capacity on that day," Ms Redmond said.

The hospital had opened a patient discharge lounge in July to free up acute beds and in October it would open a clinic for patients with chronic conditions, which represented about 70 per cent of emergency department presentations.

An expansion of the hospital due to be completed in 2016 would provide 170 more beds.

"Blacktown Hospital sits in a local government area with the fastest-growing population in Australia, and demand for emergency services continues to grow," Ms Redmond said.

Mrs Skinner said she would respond to Mr Atalla's complaint through the "standard channels".

"It was unfortunate her procedure was postponed when other more serious emergency cases were prioritised. Notwithstanding this, her wait was longer than one would have hoped – a fact acknowledged by a senior hospital manager, who extended a personal apology to her."