Hospital staff failed to properly monitor the blood sugar levels of a diabetic woman who later died after going into a coma, an inquest heard.
Claire Harry, 36, died at the Royal Cornwall Hospital in Truro in 2010.
Coroner Dr Emma Carlyon heard Ms Harry, from Penzance, fell into the coma after staff did not notice her blood sugar level had dropped, causing irreversible brain damage.
The hospital trust has apologised and said it had made changes since.
Diabetes is an incurable condition which means the body cannot control blood sugar levels because of problems with the hormone insulin.
Ms Harry, had a complex medical history, including suffering liver failure and diabetes.
She was admitted to the hospital, which had treated her for more than 12 years, on 27 September with a chest infection.
She fell into the coma as a result of hypoglycaemia [low blood sugar] on the night of 29-30 September and suffered brain damage as a result.
She never regained consciousness and died from bronchial pneumonia on 13 October, the hearing was told.
Dr Carlyon heard staff had changed the interval in which her blood sugar was monitored from every two hours to every six.
A witness told the coroner's court her case should have been reviewed by a specialist diabetes team.
In a narrative ruling, Dr Carlyon said Ms Harry died because the hypoglycaemia "was not recognised or treated in time to avoid death".
The Royal Cornwall Hospitals Trust's chief executive, Lezli Boswell, has apologised to Ms Harry's family, the hearing was told.
The trust added that 11 changes had been made at the hospital as a result of the death.
They include the provision of treatment boxes in every ward and department, extra staff on Carnkie Ward and a programme of education for all nursing staff.