A man who nearly died during an operation to donate a kidney to his sick father is claiming High Court damages of more than £14m.
The 38-year-old, who can only be identified as XYZ, was operated on at the Queen Alexandra Hospital in Portsmouth in early 2008.
He suffered "catastrophic" injuries to his other kidney and, in turn, needed a kidney transplant from his sister.
Portsmouth Hospitals NHS Trust admitted liability, the court in London heard.
Mr Justice Spencer, sitting in London, heard XYZ was the victim of a negligently performed operation.
In the course of donating his right kidney, the man suffered irreversible left kidney failure and nerve damage.
He had paid "a very great price" for assisting his father, said Elizabeth-Anne Gumbel QC.
The judge said that liability was admitted by the trust on the basis that the surgeon, who is the subject of proceedings before the General Medical Council, was not only negligent but to a degree reckless.
The four-day hearing is to assess compensation because the trust disputes some of the man's claims - including substantial amounts for future loss of earnings and medical expenses.
'Remains on edge'
Ms Gumbel said: "The donation of the kidney was successfully achieved but at a great cost to the claimant who, during the course of the operation, suffered torrential, life-threatening haemorrhaging."
She added that as a result his own life had been shortened by about 10 years.
His intention was to spare his father further dialysis treatment and give him a better quality of life in retirement.
Instead he has had to suffer the trauma of his own dialysis, considerable health problems and the prospect of future deterioration with the inevitability of another transplant, Ms Gumbel said.
"The claimant, formerly a dynamic, extremely hard-working and very highly thought of family and professional man, has been shattered by the experience," she said.
"He faces a life filled with considerable uncertainty.
"He is understandably obsessed by his health. He remains on edge as to whether the kidney will be rejected."
The hearing was adjourned until Tuesday.