More than 11 self-harm cases are recorded every week at Birmingham Prison, in what experts are calling “a national scandal”.
New Ministry of Justice figures show there were 593 cases of self-harm recorded at Birmingham Prison in 2017/18.
Of the total, 51 cases were so bad they had to go to hospital.
The 273 self-harm cases in 2017/18 is up from 202 recorded the previous year.
Modern records go back as far as 2004/05, when 109 incidents of self-harm took place.
The 593 cases of self-harm in 2017/18 is by no means the highest recorded at Birmingham Prison - in 2006/07 there were 684 incidents in the year.
Andrew Neilson, director of campaigns at the Howard League for Penal Reform, said: “The alarming rise in incidents of self-injury is a national scandal, and a direct result of a failed policy to allow the number of people behind bars to grow unchecked while starving prisons of resources.
“Cramming more and more people into overcrowded jails was a recipe for violence, drug abuse and mental distress, and although the prison population has reduced slightly over the last 12 months, the damage caused may never be repaired.
“Ministers have rightly identified that we must ease pressure on the prison system, and abolishing short sentences would be a welcome first step.
“Further action to reduce the prison population would save lives, protect staff and prevent more people being swept into deeper currents of crime and despair.”
There was also one self-inflicted death in the year to June 2018 at Birmingham Prison.
Nationally, there were 46,859 cases of self-harm recorded across all prisons in England and Wales in 2017/18 - again a record high.
It works out as more than 128 self-harm cases taking place every day.
There were a total 77 self-inflicted deaths in the year to June 2018, too.
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David Gauke, Justice Secretary, said: “Violence and self-harm in our prisons is unacceptably high and these figures underline why we are spending an extra £70m to fight the drugs plaguing prisons and boost security while also training over 4,000 new prison officers in handling the complex offender population.
“Clearly there is huge amount yet to be done but I am determined to cut the violence so prisons can focus on rehabilitating the offenders who will be back out at some point.
“And while these figures are disturbing, I am optimistic that the measures we have been putting in place will help us to reduce violence and ultimately better protect the public.”