With her hard-partying ways, singer Amy Winehouse has gone from being the music world's newest phenom to its latest casualty.

On August 8, the beehived British star was rushed to London's UCLH hospital for "exhaustion." The star's rep, Tracey Miller, says her client is very overworked.

Exhaustion takes on many meanings. For Lindsay Lohan, it likely means a liter of man soup in her stomach. For Winehouse, a source blames alcohol and drugs.

Indeed, Amy Winehouse, 23, who grew up in working-class London, has long been a wild child. Her taxi-driver dad and pharmacist mom split when she was 9. Her response?

Calling herself a "violent drunk," the singer has said she battled eating disorders, and her arm bears scars from mutilating herself.

"But the time I was 15, my parents realized I would do whatever I wanted, and that was it really," she said.

Around that time, a rebellious Amy Winehouse got her first of many tattoos and pierced her nose, which got her kicked out of theater school.

Despite the international success of her second album, Back to Black, she lacks confidence in anything other than music, friends say.

"When it comes to self-worth and looks," says a pal," she has a low opinion of herself."

This in spite of her recent marriage to Blake Fielder-Civil, who she dated off and on for a few years before rekindling the flame this spring.

In recent months, the singer, who once toiled as an entertainment reporter, canceled shows in London and L.A., and has backed out of shows in Europe.

Though her rep says that after a rest, Amy Winehouse will resume her touring schedule, friends still worry.

"Part of her problem is she has a young, strong, physical constitution and a strong mind," says childhood pal Jessica Ashby. "But they are also her solution."