British singer Adele has canceled the two final shows in her sold-out world tour over damaged vocal cords. “I went to see my throat doctor this evening because my voice didn't open up at all today and it turns out I have damaged my vocal cords,” Adele announced on Twitter late Friday. “And on medical advice I simply am unable to perform over the weekend. To say I'm heart broken would be a complete understatement,” she wrote. The singer said she noticed problems with her voice while performing at London’s Wembley stadium earlier this week, and had “even considered miming” to get through upcoming performances. “But I've never done it and I cannot in a million years do that to you. It wouldn't be the real me up there,” she wrote. She apologized to her fans and said refunds would be made to those who purchased tickets for the canceled weekend events in London.