Self-harm resulted in hundreds of hospital admissions of young people in Hertfordshire last year, new figures show.

Across England, admissions fell by a quarter, but charity Rethink Mental Illness warned many people self-harm in secret and may not be detected by these figures.

Office for Health Improvement and Disparities figures based on NHS England data show there were around 480 hospital admissions for self-harm for people aged 10 to 24 in Hertfordshire in the year to March 2023. This was down 29% from 675 during the same period the year before.

Local figures are rounded to the nearest five.

Nationally, 32,624 self-harm hospital admissions were recorded in 2022-23 – a 24% decrease on the year before, when there were 42,793.

The NHS has introduced a change to how figures are collected, so some admissions are recorded as same day care for emergency patients who would otherwise be admitted to hospital.

It said the change aims to benefit both patients and the healthcare system by reducing waiting times and hospital admissions, where appropriate.

While this could have a potential impact on the figures, only a small number of pilot providers were affected last year.

In Hertfordshire, one provider has already introduced the change.

Shaun Friel, Childline director at the NSPCC, said: “While it’s wonderful to hear that admissions to hospitals for self-harm have decreased, we cannot become complacent.

“Despite this decrease, we continue to hear all too often from children who are self-harming or thinking of ending their life.

“Children are more vocal now than ever before about their struggles with mental health and for some, their main coping mechanism is to self-harm.”

He added Childline continues to be there for all children to support them with any concern, no matter how big or small.

Across England, there were 319 admissions due to self-harm per 100,000 young people. The rate was lower in Hertfordshire, with 225.5 such admissions per 100,000.

There was also a significant difference between the rates for boys and girls in the area – 82.3 and 374.5 respectively – meaning girls were more than four times more likely to be admitted to hospital following a self-harm incident.

Jeremy Bernhaut, head of policy and influencing at Rethink Mental Illness, said: “At a time when record levels of children and young people are experiencing mental health problems, we should interpret today’s figures with caution.

“It’s important to remember that many people self-harm in secret and so a drop in hospital admissions on its own doesn’t guarantee that fewer young people are in distress.”

He said further efforts are required to understand why young girls are more likely to self-harm and how to best support all young people to improve their mental health.

An NHS spokesperson said: “Children and young people are continuing to face unprecedented pressures, with the NHS providing mental health support to more children than ever before while expanding provision as quickly as possible within the current five-year funding arrangements.

“We know there is even more to do and that’s why plans are also in place to ensure more than half of pupils can access an NHS mental health support team offering early support in schools by Spring 2025 – significantly ahead of the original target.”

Anyone under 19 can speak anonymously to a Childline counsellor about any issues they are facing by calling 0800 1111.