The terminally ill Sunderland fan, who has the rare childhood cancer neuroblastoma, has gained supporters around the world after his battle with the disease was backed by footballer Jermain Defoe.
'Bradley is deteriorating fast, his temperature is going very high his breathing very fast his oxygen levels low,' his family revealed in a statement on Facebook.
'He is sleeping most of the time apart from odd times awake,' the statement added. 'We knew this was coming but we are heart broken beyond words. We have been told he could be like this for days it just depends on him and his body.'
Bradley's mother, Gemma, posted a photo to Twitter on Wednesday of Bradley with his older brother with the caption, 'My two boys, my world, my everything'
Bradley's family announced on Wednesday that the boy's temperature has risen, his breathing speed has increased and his oxygen levels are low.
The Facebook post was followed with three broken heart emojis.
Hours later, Bradley's mother, Gemma, posted a photo of Bradley and his brother on Twitter and Facebook with the caption: 'My two boys, my world, my everything.'
Bradley's parents Gemma and Carl, from Blackhall, County Durham, have used social media to regularly update his many thousands of well-wishers around the world about his condition.
But the update on the young boy's health came after his mother asked people to stop contacting her on social media to see if he has died.
Mother Gemma told how people have been contacting her online suggesting inappropriate alternative therapies and asking if he has died.
Mrs Lowery wrote on Facebook: 'As a parent I've done and tried everything I can to cure Bradley but unfortunately nothing has worked.'
And Mrs Lowery has been forced to ask people to stop speculating about his death.
His best known supporter is footballer Jermain Defoe, for whom he has been a mascot at Sunderland and England matches
The six-year-old has won supporters around the world for his brave battle with the disease
She wrote: 'Also I really don't like to read messages saying that you think my child is going to die within the next week, asking if he has died yet, or asking if I know when he is going to die so please think of how I feel when reading that sort of thing before sending a message.'
Bradley's mother, from Blackhall, County Durham, also said she will not respond to messages recommending alternative therapies, such as cannabis oil.
Bradley was a mascot for Sunderland several times last season and struck up a remarkable friendship with top scorer Jermain Defoe.
Fans of different clubs have sung his name at matches and held banners for him.
He was also a mascot for England at Wembley when his hero scored in a World Cup Qualifier against Lithuania in his comeback game.
Earlier this week, classmates at Blackhall Colliery Primary School, Country Durham, teamed up to perform a heartwarming rendition of the song Smile for little Bradley.
The song, recorded with the help local sister act Liv 'n' G, has already soared up the charts in the iTunes top 20.