Healthline has now had 2.5 million calls. The free 24-hour phone line was set up in 2000 to answer health questions.
Since then, nearly 250,000 callers have been advised to seek emergency or other urgent care.
More than 600,000 with less serious symptoms were given advice on how to manage their condition at home.
About 80% of calls to Healthline require nurse assessment.
The telephone triage system is currently under review as the Government looks at the efficiency of the primary health sector.