A bullet that struck Malala Yousafzai, the 14-year-old Pakistani schoolgirl, has "grazed" her brain and caused physical damage to it, doctors have confirmed.
But Dr Dave Rosser, of Birmingham's Queen Elizabeth Hospital, where she is being treated, said Malala was "doing well" and had been able to stand up for the first time.
Speaking outside the hospital on Friday, Dr Rosser said the lateral part of Malala's brain had been grazed when she was shot in the head by a Taliban gunman.
"There is certainly physical damage to the brain but at the moment we are not seeing any deficit in terms of function. She is able to understand and write," he said.
He added that doctors' main cause of concern was a possible infection in the bullet track.
Dr Dave Rosser explained where the bullet had struck Malala
"Malala is still showing some signs of infection which is probably related to the bullet track, which is our key source of concern," he said.
"It's clear that Malala is not out of the woods yet.
"Having said that, she is doing very well. In fact she was standing with some help for the first time this morning when I went in to see her."
The bullet travelled past Malala's left jaw and into her neck
Dr Rosser was able to speak to the press after Malala agreed for details of her condition to be made public.
The bullet, which hit her as she made her way to school in Pakistan's Swat valley earlier this month, struck just above the back of her left eye, and into her neck.
She will need several weeks to rehabilitate and her skull may need to be reconstructed, Dr Rosser said.
He added: "Malala is keen that I thank people for their support and their interest because she is obviously aware of the amount of interest and support this has generated around the world."
Malala, who was attacked for promoting the education of girls and criticising Taliban militants, was initially treated by neurosurgeons at a Pakistani military hospital before being flown to the UK.
Dr Rosser was able to speak to press after Malala said details on her condition could be released
The teenager was shot with two classmates as they made their way home from school in north west Pakistan, in what Foreign Secretary William Hague described as a "barbaric attack".
Thousands of people from around the world have posted messages of support for the schoolgirl on the University Hospitals Birmingham NHS Foundation Trust website.
Among the postings on the message board allowing well-wishers to pass on messages of support for Malala was one from Hamna Ali, who wrote: "You are such an inspiration for all the girls in Swat and Pakistan.
"May Allah bless you with health and happiness so that you can come back and see that the whole nation is standing behind you."
The messages of good will from people in Pakistan, Bangladesh, Canada, the United States and numerous other countries included another which read: "Your extraordinary bravery and advocacy for education has touched millions of hearts throughout the world, mine among them."