The NHS is failing to offer sufficient out-of-hours GP care for severely ill patients, experts have said.
Existing services are "inadequate and inflexible" and there is a need for better diagnostic facilities, the Royal College of Physicians taskforce said.
The group also said hospital care needed to be redesigned for those with non-life threatening life conditions that none-the-less require treatment.
The government said care was improving after record investment.
The taskforce, which included a range of health professionals, looked at acute medical care.
This includes the care of patients with respiratory problems or chest pains or complications linked to epilepsy or diabetes, which are not yet emergencies but could become so.
The taskforce said poor standards of weekend and evening GP cover, which is now done by co-operatives of health professionals and private firms after family doctors were allowed to opt out in 2004, was forcing some patients to turn up at hospital for "reassurance".
The report recommended that local navigational hubs be set up to sign-post patients to the right services.
And it called for specialist outreach clinics to be set up in the community to bring expert care out of hospitals.
It said out-of-hours cover needed better access to diagnostic facilities, which includes scans and blood tests, to create a "see and treat" culture rather than the "see and greet" one that currently exists.
The experts also said hospital services needed to be redesigned to ensure "rapid streaming of patients".
The experts said that all too often even patients already in hospital can find themselves moving slowly through the system seeing nurses, junior doctors and then consultants when they really need urgent help.
They said acute medical units, rapid assessment, diagnosis and treatment centres which are becoming increasingly common in hospitals, need to be located near other key services such as the emergency department and critical care.
RCP president Professor Ian Gilmore said NHS professionals were facing a challenge - "to change what we do, when we do it and how we do it".
He added: "For doctors, nurses, managers and all those involved with the care of acutely ill patients, this task will not be easy, but the status quo is not an option if we are to give these patients a consistently high standard of care."
Health Minister Ben Bradshaw said the government welcomed the report but was already making sure that people have access to care around the clock.
"Primary Care Trusts must deliver high quality out-of-hours care, and in addition, patients have access to a range of other services that can provide urgent care out-of-hours including NHS Direct and NHS walk-in centres," he said.
"We have invested record amounts in out of hours services and patients are seeing the benefits - eight our of ten patients say that they are satisfied with the service, and six out of ten rated the service as excellent or good."