Fewer than 10 percent of patients who show up to hospital end up diagnosed with a life-threatening condition, according to a new analysis.
Nearly 2000 people were seen at Middlemore Hospital during one week in the winter of 2016, presenting with 78 different complaints.
The most common were cough, chest pain, shortness of breath, finger pain, collapse, head injury and central/generalised abdominal pain.
Of the 444 different diagnoses made, viral illness, pneumonia and lacerations were the most common.
"Only two of the top 25 diagnoses - pneumonia and [heart attack], could be classified as severe and life-threatening," the researchers wrote in the latest issue of the New Zealand Medical Journal.
"Eleven of the top 25 were classified as medium, which reflected that these diagnoses sometimes caused morbidity and occasionally mortality, but also could have limited symptomatology and be self-limiting if a milder exposure.
"The remaining 12 were classified as mild, which was defined as a diagnosis in which no cause was found, never caused death, rarely caused significant morbidity and was often self-limiting. Almost half of the top 25 diseases diagnosed at the emergency department fell into this category."
Different conditions affected different age brackets - for example, almost half of all patients presenting with cough were babies under one year of age, while two-in-five patients suffering chest pain were 65 or older.
Middlemore is the busiest hospital in Australasia, seeing around 400 patients a day on average.
It's hoped the data may help prepare medical students on what they may encounter.