Miss Lyson was diagnosed with bowel cancer in May last year when she was just 19 years old but vowed to beat the disease.
Doctors initially believed the teenager was suffering from irritable bowel syndrome when she complained of back ache and constipation.
But tests revealed she had five tumours growing on her bowel and liver. The teenager had part of her bowel removed and a colostomy bag fitted.
After her devastating diagnoses Miss Lyson set up the blog Hannah's Bowel Cancer Journey chronicling her "unwavering determination" to beat the disease.
She was confident that she could fight the condition having watched two of her sisters battle thyroid cancer and leukaemia.
In September she was positive about a recovery and talked about how her love for her boyfriend was helping her cope.
She posted a video of herself after being told that her tumours were shrinking, writing: "My results...this calls for celebration." She said: "It's been a whirlwind few months. At first my doctors were unsure but now they are feeling more positive. My outlook is much better and I feel sure I can beat this.
"I'm the first 19-year-old with bowel cancer at the hospital so my doctors are not sure how my body will react but I'm doing so well."
But earlier this month, Miss Lyson, who had recently celebrated her 20th birthday, revealed her body was not fighting the cancer or responding to treatment.
She was told this month that there was nothing doctors could do nothing to save her and her chemotherapy treatment was stopped.
Bravely describing the moment on her blog, she wrote: "I'm not writing a blog post as I don't have the effort or ability right now but sadly today we've been given the worst news imaginable.
"Sadly, the doctors have decided there's no more chemo for me and the liver is winning this fight and I am losing."She added: "I've tried so hard and me and my family are absolutely distraught so please respect our privacy during this time.
"Maybe at some point I will write a blog post but right now I'm now feeling up to it."
