A House of Lords committee report states the NHS is "an iconic part of Britain's social fabric" but suggests the system is not sustainable in its current form.
Peers said there are a number of "threats" which undermine the future of the NHS, including the rising tide of obesity and other preventable illnesses, an "over-reliance" on hospitals and the "funding crisis" in adult social care.
The report made a raft of recommendations for government to secure the future of the health service including a new campaign to highlight the obesity "epidemic" and a new body to oversee the long-term future of the NHS.
Ministers should also look into a new insurance scheme to enable people to prepare for their care needs in older age.
The peers said the health service should remain tax funded, and free at the point of use, but in coming years this will require "a shift in government priorities or increases in taxation".
The report, from the House of Lords Select Committee on the long-term sustainability of the NHS, slammed the "short-sightedness" of successive governments to plan ahead.
An office for health and care sustainability should be established to look 15 to 20 years ahead to "counter the endemic NHS disease of short-termism".
Meanwhile, peers called for a new campaign to highlight the issues caused by obesity after claiming the issue is a "significant threat to the sustainability of the health service".
Preventable health problems as a whole are putting a "significant burden" on the system, they added.
Another major threat is the funding issues in social care, which is "on the brink of collapse", the authors added.
New money pumped into the social care system was welcomed but peers said it is "clearly insufficient to make up for many years of underfunding".
The authors wrote: "The funding crisis in adult social care is worsening to the point of imminent breakdown.
"Pressures in social care are the greatest external threat to the long-term sustainability of the NHS."
They suggested social care funding should come from the Department of Health, which should be renamed the Department of Health and Care.
Ministers should also give consideration to the introduction of an insurance-based scheme which would start in middle age to cover care costs.
Such a scheme could replicate ones already in place in Japan and Germany, both of which involve compulsory long-term care insurance which is shared between an employer and employee, much like the workplace pension scheme in the UK.
Meanwhile, the report suggests NHS England and NHS Improvement should be merged as peers could not see the case for two separate national bodies.
Overall, they said that to achieve long-term sustainability of the NHS there needs to be "radical" service transformation, "immediate and sustained action on adult social care" and long-term funding solutions for the NHS and adult social care.
They said the reduction in health spending as a share of GDP seen over this decade cannot continue beyond 2020 without seriously affecting the quality of and access to care.
Committee chairman cross-bench peer Lord Patel said: "The Department of Health at both the political and official level is failing to think beyond the next few years.
"There is a shocking lack of long-term strategic planning in the NHS.
"This short-sightedness stems from the political importance of the NHS and the temptation for politicians to reach for short-term fixes, not long-term solutions."
A Department of Health spokesman said: "We are totally committed to an NHS, free at the point of use, providing world-class care - and we agree that means taking decisions to ensure the sustainability of the service in future.
"That's why we are already expanding the number of medical training places by 25% to ensure we have all the doctors we need, investing in social care and working on a long-term funding solution in a green paper, and putting £325 million into local transformation plans to improve services, with more to follow in the autumn."
An NHS England spokesman said: "The Lords committee makes a number of important long-term recommendations well worth proper debate and consideration."