ABU DHABI, United Arab Emirates — Before she arrived in this mecca of migrant labor at age 48, Evelyn Naces, a Filipino nurse, had never owned a credit card. Soon she had 14 of them — and like thousands of other foreign workers here, a trip to debtors’ prison.

“When they put me in shackles, that was the worst,” said Ms. Naces, who had $27,000 in unpaid bills, mostly from helping her grown son start a business back in the Philippines that later failed. “I felt so degraded.”

For years, banks all but threw credit cards at the foreigners who come here in droves to work the malls and fill the office towers. The workers, many of them raised in poor countries and new to easy credit, spent beyond their means. Staggering losses followed, with jail terms common for those who could not pay.

Whether cast as reckless lending or heedless borrowing, their stories offer an unusual glimpse of the hidden emotions — webs of pride, guilt and family obligation — that follow millions of migrants across the globe.