Cutting and scratching is the most common form of self harm
The idea that self-harm is almost exclusively a problem among teenage girls is wrong, research suggests.
Almost 1,000 people with a history of self-harm responded to a survey by UK mental health charity Sane.
More than 10% were male, and the researchers said it was possible that boys simply concealed their self-harm more than girls.
In addition, some respondents said they did not start harming themselves until they were in their fifties.
Others reported that they first started to harm themselves when they were as young as four.
MOST COMMON METHODS
Cutting and scratching: 93%
Buring the skin: 28%
Bruising the body: 17%
Almost half of the 532 people who were still self- harming when they answered the survey had been harming for more than five years, and a quarter for at least 11 years.
Of those, 20% were hurting themselves daily and 30% were harming themselves weekly.
The survey also suggests far from being a way to seek attention, self-harm is generally hidden, often out of fear about the impact on family and friends.
Some 84% of respondents tried to hide their behaviour from their family, and 66% tried to hide it from friends.
Many said they chose to damage a part of their body that was easy to conceal from others, or where the injury could be most easily explained away as an accident.
Only one person in eight said their first act of self-harm was motivated by a desire for others to take notice and care, and this figure dropped to one in 12 for subsequent acts of self-harm.
BODY PARTS HARMED
Thighs or legs: 50%
Many people said they did not expect those closest to them to understand why they had self harmed.
While people who harm themselves do appear at higher risk of suicide, the survey found most of the time self harm is actually an attempt to alleviate suicidal thoughts.
Marjorie Wallace, chief executive of Sane, said the study showed a wide mix of people harmed themselves.
She said: "What is alarming is the numbers of those taken to A&E departments who are sent home without any follow-up help.
"We need doctors and teachers to be more alert to the potential risks, and many more therapists available, to prevent the vicious cycle of relief by painful self-harm."
Ian Hulatt, mental health adviser at the Royal College of Nursing, welcomed the report for focusing on how to care for people who have harmed themselves.
He said: "Self-harm remains a challenging and often unspoken subject."
Research suggests the UK has the highest rate of self harm in Europe.
The number of children admitted to hospital due to self-harm rose by a third in five years to 2007.