Richard Harrison fell in the room at the house where he lived with his parents on Troon Road, Hatfield, after the fall, in which he struck his head against a chest of drawers, an inquest heard.
It is the second tragedy suffered by his family, who lost his older brother in a lorry crash in 2006.
Mum Janet Harrison told Doncaster coroner Mark Beresford in a statement that her son, Richard, had refused to go the hospital with the injury, which happened in the early hours of September 24, last year
But when his parents tried to wake him up, they were unable to get a response from him.
Mrs Harrison said: "At 2am I heard him fall. I could see a cut to his head. It looked like he had cut his head on the corner of the cabinet.
"I told him he needed to go to hospital. He was sober, he had not had a drink. He refused to go to hospital and stayed at home.
Paramedics came out and he was taken to hospital and put on a ventilator.
Tests found a bleed on Richard's brain and damage to his brain stem, consultant neurosurgeon Dev Bhattacharyya told the hearing in a statement. He performed an emergency operation to try to save him.
But Richard never regained consciousness, and the decision to turn off his life support machine was made on October 7.
The inquest heard the former calls centre worker had developed a drugs problems 11 years ago after the death of his brother in a road traffic collision.
Older brother John was killed aged 28 when he was thrown through the windscreen of a truck in September in September 2006. He died after the vehicle in which he was a passenger collided with a lamppost next to Doncaster Road, Dunsville.
Richard had received treatment for his addiction, but also started to drink and was described as drinking on average three bottles of wine a day.
Coroner Mr Beresford recorded a verdict of accidental death. He said the cause of death was brain stem damage due to serious head injuries sustained in a fall.