“You are making nice money. But the trade-off is also big,” said Vats, who spent nearly two years at an IBM Corp. call center handling customer calls from the United States.

Call centers and other outsourced businesses — such as software writing, medical transcription and back-office tasks — employ more than 1.6 million people in India, mostly in their 20s and 30s. But at this young age, they face sleep disorders, heart disease, depression and family discord, according to doctors and several industry surveys. …

Most call center jobs involve responding to phone calls through the night from customers in the United States and Europe, some of whom can be angry and rude. It’s monotonous and there is little meaningful personal interaction among co-workers.

“There are times when the stress is so overwhelming that they fail to cope with it,” said Archana Bisht, who started a counseling company — 1to1help.net — in Bangalore six years ago. …

About 32% of respondents complained of sleep disorders, 25% had digestive troubles and 20% reported eyesight problems, according to the survey, which covered 1,749 employees.

Read: A cry for help at India’s call centers