Singer Amy Winehouse has lung damage and an irregular heartbeat, her father said in an interview published Sunday.

Ms. Winehouse has damaged her lungs by smoking crack cocaine and cigarettes. The Sunday Mirror quoted Mitch Winehouse as saying that his daughter has early-stage emphysema and an irregular heartbeat, and has been warned that she will have to wear an oxygen mask unless she stops smoking drugs.

“The doctors have told her if she goes back to smoking drugs, it won’t just ruin her voice, it will kill her,” Mr. Winehouse was quoted as saying. “There are nodules around the chest and dark marks. She has 70% lung capacity.”

Ms. Winehouse collapsed at her North London home Monday after signing autographs for a group of fans and was taken to a London hospital for tests. She remained there all week. She is still scheduled to sing at a concert in London on Friday celebrating the 90th birthday of Nelson Mandela, the South African Nobel Prize winner, and plans to take part in the Glastonbury music festival the following day.

Her father pleaded with her drug-taking friends to stay away from her.

“What hope does she have if people are taking drugs around her,” he said.