The hospital staff only see the injuries and they treat me as someone who cannot cope. I'm holding down a job that I do well and looking after my children. I have friends and am part of my community. But that gets disregarded."

Self-harming: it is often seen as an issue affecting teenagers. But a new survey being released today by the charity Outside the Box makes clear that women and men over 25 also injure themselves, including people aged in their sixties, and some have been doing so for more than 20 years. Often they are working and caring for others, and specialist support services for them are non-existent.

Drawing on responses from adults who self-harm, and the friends, relatives and professionals who care for them, the Outside the Box report highlights the need to raise awareness and understanding of the issue among the public and health professionals.

Self-harming, inflicting injury on oneself, is "a way of expressing deep emotional feelings or problems that build up inside", according to NHS Direct.

The most readily recognised form is cutting the skin, but it can take several others. Smoking too much, and binge-eating, drinking or misusing drugs to excess, can be seen as types of self-injury.

Outside the Box, which supports people and groups who tend to be marginalised, including people with mental health problems, produced its report after speaking to women aged 30 to 50 who self-harmed or were worried about friends who did, and wanted information about other older people in the same situation. The survey, which was online and confidential, received 84 responses, including 46 from people who self-harmed or had done so in the past. Of them, three-quarters were aged 25-44 and the remainder were older. Most were working and 41 of them were women.

Past research has shown that there is a higher prevalence in the lesbian, gay, bisexual and transgender community. One-third of the people who took part put themselves in this category.

One of the most striking findings was that the overwhelming majority of people - 38 out of 46 - had been self-harming for more than five years and more than half for more than 10 years. Seven people had been harming themselves for more than 20 years.

A number stressed that their behaviour was not about suicide. One said: "I self-harm because I do want to be alive and sometimes hurting myself is the only thing that helps me hold on and stay alive, stay in the world."

Perhaps surprisingly for a behaviour that is often seen as secretive, most respondents said at least one or two people among their family and friends knew about their self-harming, though not all felt their relatives were supportive. What came across loud and clear was that many considered their self-harm to be a mental-health issue, though not necessarily linked to mental illness. "I don't think self-harm is a psychiatric issue but it is definitely a mental health issue," said one.

It is more easily defined as a "behaviour" than a diagnosis in traditional terms, says Charlie McMillan, director of research, influence and change at Scottish Action on Mental Health. "Professionals see it in different ways: some see it as a coping strategy, some as a cry for help, some as an indication that something is not right and we need to work with the individual involved. There are a number of ways of interpreting self-harm. The important thing is to listen to the person concerned: it may be that they are depressed or anxious; they may see it as a coping strategy - there will be no one rule for all.

"What we hear time and time again is that the thing that helps people the most is being listened to, being heard and treated with respect and dignity. From there, you can lead on to a discussion about how you deal with it."

That is very much in keeping with the views expressed by the survey respondents. Most decribed positive experiences with their GP or A&E department, but a significant number said they had not been treated well.

For example, one said: "The A&E consultant of my local hospital has been great and made arrangements to make sure I get continuity of care. He also stated that it did not matter how many scars I already had, each injury should be treated as carefully as possibly to promote good healing and reduce scarring"; while another said: "Staff were rude and I heard them saying that they are sick of people like that' wasting their time."

The respondents stressed that they didn't want to be judged, but to be treated with respect, and felt a greater understanding of self-harm among health professionals would improve matters. They also called for more support and information for the families and friends of people who self-harm.

Anne Connor, chief executive of Outside the Box, confirms that within existing specialist support services for people who self-harm in Scotland, the maximum age for referrals is typically 21 and in a few cases 25. She says that, in short, there are two priority areas where progress is needed. The first is simply recognising the reality. "Self-harm exists. Don't freak out about it, it's there. That being recognised in itself makes it so much easier for people to talk about it.

"The second thing is that services should respond to people in a sensitive way. What is clear is that some people are getting wonderful caring support while others are not."

The last word goes to one respondent who was asked how people should be treated by GPs or A&E staff: "Calmly, and with respect."