GPC negotiator Dr Beth McCarron-Nash called for a national awareness campaign to help patients care for their own health and an 'honest and open' debate about what the NHS can afford.
Meanwhile, Sir Bruce Keogh's report into the future of urgent care in England said patients need better support to self-care, to avoid the need to see a healthcare professional in some cases.
Minor ailments account for one in five GP consultations, costing the NHS £2bn a year.
Speaking at the Self Care Conference 2013 in London on Tuesday, Dr McCarron-Nash, a member of the Self Care Forum's board, said expectations of the NHS had grown at a time of rising chronic illness in an ageing society.
She said: 'We need to be much better at targeting our resources to those who actually have the most need.
'I absolutely, fundamentally believe that unless we actually start to address the issues of self care, and enabling patients to work with us as equal partners, the NHS, in my personal view, will be unsustainable.'
She called on NHS England to introduce a national campaign to educate the population about how and when to care for themselves at home.
'We need to start actually having a conversation with patients about how we can enable them to optimise their health, how they can stay well, how they can use other services other than the default position being, "I'll just go to my GP".'
Speaking to GP at the event, Dr McCarron-Nash said CCGs needed to provide incentives for practices to offer this support to patients.
GPs need to 'consider advising patients [to self care], really as a coping strategy to help us manage demand, so that patients are accessing services when it's most appropriate for their health need', she said.
'Long term, that will have an effect on your consultation rates, on your prescribing budgets, on the wellbeing of your patients.'
But she stressed: 'This isn't about saying to people, don't come.'
Dr McCarron-Nash called for a public debate on the public's 'responsibilities' when using the NHS. 'There has never been an open debate, in public, about the NHS sustainability and demand.
'But we need to have that debate with the public. We either end up having to pay more, if that's what we want, or we risk it not being there in the future.'