Nearly 10,000 people a week fail to turn up for an appointment with their GP or nurse across Northern Ireland, a GP survey said.
Health authorities urged people to think carefully about how they use services this winter.
BMA Northern Ireland Council chairman Dr John Woods said: "It is vital that we all choose the appropriate service for our healthcare needs, particularly during the winter months when demand for GP and out-of-hours services is higher.
"It is also crucial that people keep any appointments they have made or inform the practice if they no longer need to see a doctor so that others can benefit.
"Many common ailments can also be treated effectively through self-care or by a pharmacist. However those with serious concerns about their health should of course always consult their GP or an out-of-hours service."
The non-attendance figures, based on a survey carried out in GP practices last year, showed that more than 5,000 people failed to turn up for a GP appointment and around 4,500 missed an appointment with a nurse.
The statistics were released by the Health and Social Care Board (HSCB) at the launch of the Choose Well campaign which urges people to think this winter about how they use health and social care services if they or their family become unwell or have an accident.
The campaign will include three new radio ads focusing on self-care, emergency departments and mental health, as well as a range of TV, outdoor and newspaper advertising and other activity.