Euro zone purchasing managers index (PMI) data showed a rebound in July, but analysts warned that the region faced severe headwinds in the coming months which could impede, and even reverse, the region's return to growth.
Economic activity expanded in July for the first time since January 2012, PMI readings released on Wednesday showed.
(Read more: Euro zone business activity expands, euro rallies)
The data boosted stocks and caused the euro to rally to a one-month high against the dollar. But economists pointed out that the improved readings were likely to lead to a very small uptick in growth in the third quarter.
Kit Juckes, the global head of foreign exchange strategy at Societe Generale, told CNBC that the European recession was ending but only "to be replaced by European stagnation".
Chris Williamson, chief economist at Markit, which publishes the PMI data, predicted growth forecasts for the third quarter would be revised up to 0.2 to 0.3 percent from the current estimate of 0.1 percent.
However, he cautioned, much depended on the global environment, political situation, corporate investment and consumer demand - hardly small obstacles for the euro zone to surmount.
(Read more: Is a perfect storm brewing in euro zone?)
The upside for domestic demand in the euro zone was also likely to remain constrained, Howard Archer, chief U.K. and European economist at IHS Global Insight, told CNBC.
"Widespread restrictive fiscal policy, persistently tight credit conditions in many countries, very high and still rising unemployment and limited consumer purchasing power [are all factors that could constrain growth]," Archer said.