THE PATIENT IS A little less feverish, but his condition is very poor and the long-term prognosis is grim. That about sums up the General Accounting Office's latest review of New York City's fiscal ill health. Although the city's financial managers are straightening out its bookkeeping, cutting spending and surviving one debt deadline after another, GAO predicts that they are unlikely to balance the budget by mid-1978. Even if that goal can be achieved, GAO concludes, the city's needs "will remain very heavy" and fiscal crisis and dependence could become permanent states.

New York's ills, the report underscores, are not caused just by past extravagance and budget-juggling. The city is afflicted in an especially acute way by the large economic changes that have been remarked on so much recently - the relative decline of manufacturing and the great migration of people, jobs and investment from older industrial centers to warmer, energy-rich regions of the South and West. In New York this erosion is gaining speed; after losing 180,000 manufacturing jobs in the 1960s, the city has lost 468,000 more since 1970.

Although New York is the worst case, the basic infirmities are regional. That is dramatized once more by the Advisory Commission on Intergovernmental Relations' new report on the fiscal "blood pressure" of the states. The findings are not surprising. As of 1975, tax burdens are highest and had risen most rapidly in New York State. Massachusetts was next, as any Boston taxpayer could guess. Of the 16 states showing the greatest fiscal stress, 13 - all but California, Nevada and Hawaii - were in the Northeast or industrial Midwest. Except for New Hampshire, the states with low and falling fiscal pressures were primarily in the South and West. And these regional disparities were increasing, ACIR found.

Both reports confirm the mounting problems that have spurred officials in the "snowbelt" states to campaign for changes in federal-aid formulas, federal assumption of more welfare costs and other infusions of aid. But the GAO and the ACIR both caution against huge, hasty regional rescue attempts. The ACIR report emphasizes the need for more understanding of differences among the slow-growth states, and notes the political difficulty of defining any area's fiscal needs - as distinct from the level of public services its residents have enjoyed until now. In a complementary note, the GAO report warns that increased federal aid to New York and other struggling cities could easily become a permanent national drain unless the cities' economic foundations can be revitalized somehow.

All this indicates that the Carter administration is on the right general course in seeking not only some immediate federal help for the hardest-hit cities and states, but also ways to stimulate long-term economic revival there. However, contering major economic tides is a complex business and chancy at best. As the GAO report notes, "the record of regional development efforts is spotty, both here and abroad." So there is every reason to try experiments such as the administration's proposed $400-million fund for development programs in cities that can get themselves organized. And, as Treasury Secretary W. Michael Blumenthal seems to recognize, there is equal reason to move very cautiously on more portentous projects, such as an urban reconstruction bank. A lot of basic questions about the evolution of older parts of America have barely begun to be discussed.