Celebrity TV dentist Dr Uchenna Okoye has died after a "sudden illness", her representatives have said.
The 53-year-old starred on makeover show 10 Years Younger and was a regular contributor on ITV's This Morning.
Tributes have poured in on social media, with fans writing of their "shock" and sadness.
Dr Okoye died after a "sudden illness" on Friday, according to a statement on her Instagram page.
Her representatives told Sky News the mother-of-one was taken ill at home.
They added: "At this time, we ask for your prayers for her young daughter, her family, her team of staff at London Smiling Dental Group and her friends who are all struggling to come to terms with her loss."
Dr Okoye was a medical expert on ITV's This Morning and contributed to a string of other programmes, newspapers and magazines.
She was perhaps best known for appearing on 10 Years Younger, which started on Channel 4, and its spin-off show 10 Years Younger In 10 Days on Channel 5.
She also ran two London dental practices and had her own range of dental products.
According to an online profile of Dr Okoye, she qualified at Guy's Hospital in London and was an expert in cosmetic dentistry.
She was an honorary clinician at St George's Hospital in London and clinical director of London Smiling Dental Group.
'Absolute force of a human being'
10 Years Younger presenter Cherry Healey was among those paying tribute.
She wrote on Instagram: "There aren't really the right words to say how much this absolute force of a human being will be missed and how sad this news is.
"I was so fortunate to work with Dr Uchenna on @10yearsyounger for many happy years, and to then got to know her as a beautiful friend."
She added: "She spoke with such passion and love for the people she helped smile again - and she was the warmest, smartest, most fun woman you could wish to meet."