Lee Gorman, 25, signed himself out of Coventry and Warwickshire Hospital despite warnings that a blood clot in his leg could move to other parts of his body.
He was told that too much movement of his leg could have serious consequences. The inquest was told that 10 minutes after arriving home Mr Gorman, of Radford, West Midlands, was complaining of a shortage of breath.
He was taken to hospital but was certified dead in the resuscitation room. A post-mortem examination revealed that he died from a blood clot on the lungs.
The Coventry inquest was told that Mr Gorman, who was unemployed and had two young children, first visited the casualty department on 11 May after falling off a three-wheeled motor bike near his home.
He was suffering from broken foot bones. The next day his foot was put in plaster and Mr Gorman was told to rest it.
But on 20 May he returned to the casualty department complaining of leg pains. He was admitted to hospital and put on a course of drugs and treatment to dissolve blood clots which had developed in his leg.
Dr Philip Clithero, a registrar at Coventry and Warwickshire Hospital, told the inquest that after a week's treatment, Mr Gorman started talking about discharging himself.
Dr Clithero said: 'He discussed it with staff. I had quite a long conversation with him because he wanted to discharge himself.'
He said that despite his warnings that the blood clot might travel through his system, Mr Gorman signed himself out on 29 May.
The woman he lived with, Jackelyn Rawlings, said he was normally fit and healthy and had become restless in hospital. She said: 'He just wanted to come home.' But she added: 'Within 10 minutes he was lying on the bed and said he was short of breath.'
The coroner David Sarginson said: 'It seems to me without doubt he should not have discharged himself from hospital.'
He recorded a verdict of accidental death.