A mother says she thought her disabled son was going to die after an "unprovoked attack" on a night out.
Martyn Griffiths, 32, who is awaiting a heart and lung transplant, was injured in an incident at Aberdare town centre in the Cynon Valley early on Saturday.
He was knocked out but later regained consciousness and is being treated at hospital in Merthyr Tydfil.
South Wales Police said one man had been arrested and bailed, and inquiries were continuing.
Mr Griffiths's mother Janette Leonard said her son had battled against health problems since he was a baby.
She said she had always tried to ensure he enjoyed as normal a life as possible.
"He's very physically disabled and he's very vulnerable. He wanted to go out with his friends so off he went," she said.
"He's 32 but he looks like a 13-year-old or an 80-year-old. He's a very vulnerable adult."
She added: "I've always tried to make him as independent as possible despite his disabilities. I've always encouraged him to do the most he can in life."
Ms Leonard received a call from police in the early hours of Saturday saying her son had been hurt, so she rushed to the scene.
Mr Griffiths had regained consciousness when she arrived and was waiting for an ambulance, but his condition suddenly deteriorated.
"He said he had severe chest pains and I thought he was dying. I said to the ambulance people 'you've got to come quickly'.
"They still said 'you will get an ambulance through but it might be an hour or two'.
"I thought he was going to die. The taxi driver said 'get in the car and we will go over', and he took us to the hospital."
'Heart problems'
Mr Griffiths was treated at Prince Charles Hospital and his mother hoped he would be discharged on Sunday afternoon.
She said his face was "battered" but he seemed to be physically okay.
Mr Griffiths has been in and out of hospital since he was a baby and was given one of his mother's kidneys in an operation about 10 years ago.
She said he had suffered from kidney, heart and lung problems.
"He's had operations in the [Royal] Brompton hospital in London since he was six months old," said Ms Leonard.
"He was born with heart problems. He's on the list at the moment for a heart and lung transplant."
A South Wales Police spokesperson said: "In the early hours of the 3rd April, an assault was reported to police near to New Look in Aberdare.
"One male has been arrested and bailed, and inquiries are continuing."
In response to Ms Leonard's concern about the waiting time for an ambulance, a Welsh Ambulance Service spokesperson said: "We are unable to comment on individual cases but if the patient or his family wish to contact us we would be happy to discuss it directly with them."
BBC News
