A student bit her nails so much, she had to have her thumb amputated.
Courtney Whithorn, now 20, developed the habit when she was bullied at school and in 2014, she bit off her entire thumb nail, with the digit then turning black.
The embarrassed then-teenager kept it hidden for four years by wearing false nails and keeping her hand in a fist, but it later transpired she had caused such major trauma to her nail bed, it developed into a rare cancer called acral lentiginous subungual melanoma.
Courtney, who lives in Australia but is originally from North East England, said: ''When I found out that biting my nail off was the cause of the cancer it shattered me. In my head I thought ''I've done this to myself'' but obviously I knew I shouldn't have that mentality. I couldn't believe it.''
Following her diagnosis in July, Courtney has had four surgeries and the final one last week saw her thumb completely removed.