Jessie J's hair 'is falling out like crazy' Jessie J's "perspective" has changed after undergoing surgery in June. 13 August 2025 Jessie J's hair was falling out "like crazy" after she underwent surgery. Jessie J has opened up about her struggles The 37-year-old pop star underwent a mastectomy in June, after being diagnosed with breast cancer, and in a video filmed two weeks ago, Jessie revealed the physical toll of her surgery. In a video posted on Instagram, and filmed before a TV show appearance, Jessie explains: "My hair has been falling out like crazy since the surgery.