Patients in England will soon be able to enter symptoms online and receive tailored advice or a call back from a health professional.
Details of the new online NHS 111 service will be outlined in a speech by Health Secretary Jeremy Hunt in Manchester on Wednesday.
The NHS.uk website will allow patients to book appointments, access medical records and order prescriptions.
The initiatives are part of moves towards a paperless NHS.
It was announced in February this year that £4bn had been set aside for the IT initiative.
The new online triage system is part of an expansion of the current NHS 111 non-emergency phone line service.
The service is being developed with leading clinicians and will be piloted before the public can use it.
The relaunched NHS website will also allow patients to compare how well their local health services perform in areas of dementia, diabetes and learning disability services.
Data on maternity, cancer and mental health data will be added in the autumn.
The site will also have a new collection of NHS-approved health apps to guide patient choice.
Mr Hunt will say the new plans “will make it easier for patients to get medical support and information they need, and should encourage more of us to use the growing range of online NHS services available”.
“We live in the age of the smartphone, and we want the NHS to reflect that,” he will say.
“This is a way of supplementing patients seeing their doctor in a more conventional, face-to-face setting, and crucially it will give people more choice and the opportunity to access healthcare in a way that works for them.”
In 2012 ministers had promised that within three years patients in England would be able to book GP appointments and get test results online.
In 2013 Mr Hunt said he wanted the NHS to be paperless by 2018 – with the first step, giving people online access to their health records supposed to be available by March 2015.
A report suggested better use of technology could allow £4.4bn to be put back into the NHS.