The Sunday Mirror quoted Mitch Winehouse as saying that Amy has an 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.
http://www.cnn.com/2008/SHOWBIZ/Music/06/22/winehouse.health.ap/index.html
http://www.cnn.com/2008/SHOWBIZ/Music/06/22/winehouse.health.ap/index.html