Thousands of children have type 1 diabetes and do not know it, according to a hospital doctor.
The condition is not being diagnosed unless the child gives out a "warning sign", said Dr Julie Edge, a consultant paediatric diabetologist at John Radcliffe Hospital in Oxford.
One in every four of the 29,000 children who have type 1 diabetes only get diagnosed with the condition after they have a diabetic ketoacidosis (DKA) attack.
DKA develops from severely high blood-glucose levels and usually only occurs in people who have fully blown type 1. The attack can result in vomiting, rapid breathing, nausea, stomach pain and sometimes even coma.
Around 35% of children diagnosed with type 1 diabetes before they reach the age of five have had DKA, Dr Edge said.
She has compiled a report on the problem of late diagnosis, which will be published in the British Medical Journal.
A consultant paediatric endocrinologist and diabetologist at Nottingham University Hospital has also urged parents to take action if they see any of those potential symptoms. Dr Tabitha Randell said that frequent urination such as bed wetting was not always just a sign of stress.