David Cameron said the NHS is safe in his hands as he brought the annual Conservative conference to an end.
Mr Cameron accused Labour of mismanaging the health service and said he would be taking to the streets with a campaign to stop the cuts.
The Tory leader also hit out at those accusing him of peddling spin rather than substance.
He warned against rushing out policies and argued the Conservatives were "getting ready to serve again".
Mr Cameron called the NHS was one of the 20th Century's greatest achievements.
"Tony Blair explained his priorities in three words: education, education, education," he told Tory activists in Bournemouth.
"I can do it in three letters: NHS."
Mr Cameron, who has a severely disabled son, continued: "When your family relies on the NHS all of the time - day after day, night after night - you know how precious it is.
"So, for me, it is not just a question of saying the NHS is safe in my hands - of course it will be. My family is so often in the hands of the NHS, so I want them to be safe there."
He promised "no more pointless and disruptive reorganisations". Instead, change would be "driven by the wishes and needs of NHS professionals and patients".
No easy answers
At the end of a week which has seen demands for tax cuts from senior party figures such as backbencher Edward Leigh, he once again insisted he would make no "pie in the sky" promises.
He said: "I want to deal with this issue about substance. Substance is not about a 10-point plan, it is about deeper things than that. It is about knowing what you believe, it is about sticking to your guns.
"It is about taking time to think things through, not trotting out the easy answers that people want to hear.
"It is about character, and judgement, and consistency. It is about policy, yes. But it is about developing policy for the long-term."
'No sacking for Boris'
Mr Cameron did say that he believed a low tax economy was a strong economy.
On other issues, he said immigrants should learn to speak English.
He also backed the creation of new faith schools, adding that Muslim schools must admit a quarter of pupils from non-Muslim backgrounds - as Church of England schools are now set to do.
"If these schools are to be British state schools, they must be part of our society, not separate from it. So they must do more than provide a good education," he said.
All schools must teach children that wherever they came from they are "inheritors of a British birthright", he argued.
Tony Blair has attacked the Tories for distancing themselves from both Europe and the White House.
But Mr Cameron said he wanted a "steadfast not slavish" relationship with America and said he pleaded guilty to "wanting to be a British prime minister pursuing a British foreign policy".
On the environment, Mr Cameron urged Tony Blair to use the Queen's Speech to promise new legally binding targets for cutting greenhouse gas emissions.
He also attacked Labour's record on crime, promising to tackle the causes of crime.
And he said he wanted to replace the Human Rights Act with a British bill of rights to ensure the fight against terrorism was not hampered.
Mr Cameron also said there was "something special" about marriage - a "vital institution" which must be valued more through tax breaks, flexible working, family centres and relationship centres.
And backing civil partnerships, he said marriage meant something "whether you're a man and a woman, a woman and a woman or a man and another man".
The last day of conference has also seen maverick frontbencher Boris Johnson hail chef Jamie Oliver as a "messiah" after appearing to criticise his healthy school meals campaign a day earlier.
Mr Cameron joked that having Mr Johnson on his team showed the Conservatives, unlike New Labour, did not mind people going off message sometimes.