St John ambulance has apologised to a female patient and disciplined a paramedic who told her she had a throat infection and hadn't drunk enough water when she actually had pneumonia.

An internal investigation also found the staff member had made inappropriate comments about the woman's anxious mother, which the ambulance service has labelled "extremely unprofessional, offensive and unwarranted".

The Herald has agreed not to name the woman, now 29, or her mother.

Two St John paramedics were called to the woman's East Auckland home in July 2017 after her mother called 111, saying her daughter was struggling to breathe.

The woman told the Herald the male paramedic told her she had "brought this on herself for not drinking enough water", after saying she didn't like water much.

"I was very upset, I was made to feel as though I was wasting his time and that neither me or my symptoms mattered. I was apparently just being dramatic," the woman said.

Her mother told the Herald the male paramedic diagnosed her daughter with a throat infection and made the comment that "there were already 600 patients at Middlemore ED just like her".

The mother said she was shocked as she was genuinely fearing for her daughter's life at the time.

"I could see she was terrified and he ... wouldn't help her," the mother said.

"My daughter then told me that while in the back of the ambulance, the male paramedic said to his partner they should have been treating the mother and pointed to his head and alluded that I was unhinged."

The woman was diagnosed with pneumonia once she got to hospital and remained unwell for several months.

Her mother laid a complaint with St John.

In an email obtained by the Herald, St John referred to its investigation into the complaint, finding the woman was not fully and thoroughly assessed before being taken to hospital.

Then-Counties territory manager, Glenn Metcalfe, said the male paramedic "may have been trying to relay a message about Middlemore being very busy" when he made the comment.

Metcalfe said there was evidence the paramedic made a comment about the woman's mother, describing the comments as "extremely unprofessional, offensive and unwarranted".

Regarding the water remark, Metcalfe said there was no evidence the woman was dehydrated, calling the comment unnecessary.

A second review of the woman's case was taken up by the head of Patient Safety and Quality, who found inappropriate comments were made by the male paramedic.

St John acknowledged the full review of the complaint highlighted "a number of deficiencies" in the service given to the woman, saying disciplinary action would be taken.

In a statement to the Herald, Metcalfe, now Auckland District operations manager, said: "While the ambulance officer remains employed by St John he has completed a performance improvement plan (PIP) and both the ambulance officer and St John have apologised to the patient and their family. St John reiterates our apology."

The woman said the ordeal had meant she had lost all faith in St John . She believes the male paramedic should have lost his job.

"What if I had listened to him and remained at home following his wrong diagnosis? I am not sure I would be here today to tell this story."