The little girl from Xi'an, Shaanxi Province of China, has an undiagnosed condition which causes her feet to grow at an extremely quick rate.
Both her feet are growing far too big for her body, and are constantly swollen and heavy, making each step painful for the little girl.
An X-ray that the family have of Yu Yu's feet show they are malformed and curve outwards.
Her family are slowly raising funds to take their little girl to a doctor in Beijing for help with her condition. Her grandfather is collecting money by selling pigs until they have enough to pay for a proper diagnosis and possible treatment.
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