SINGER Amy Winehouse has begun to rehearse for her upcoming concerts, despite having treatment in hospital for traces of lung disease emphysema. A spokesman for the star confirmed she has returned to work, but must go back to hospital for further treatment. She is due to perform at a gig to mark Nelson Mandela's 90th birthday and Glastonbury festival at the weekend. Her spokesman added it "looks likely" she will sing but they are awaiting "the final sign-off" from the doctors. On Monday Winehouse's father told BBC Radio 1 his daughter had been "responding brilliantly to treatment" and she would recover "completely" as long as she stopped smoking. Winehouse's US publicist told an American news agency her condition was not serious. "She is not diagnosed with full-blown emphysema, but instead has early signs of what could lead to emphysema." The singer's spokesman in the UK said her father had "muddied the water" because he is "not a medical man". The spokesman added: "She has something that could lead to emphysema and has to do the right things to stop that happening."                       - BBC