I have someone extremely close to me who is considering selfharm and has told me this, I have tried telling them that no good comes out of selfharm as I know from personal experience (I selfharmed when a close relative of mine passed away and I couldn't cope with that well, I haven't selfharmed since, the loved one who is considering selfharm knows about this and told me I never should have done it). The circumstances in which the person wants to selfharm because of is not one caused by the passing away of a loved one, failure in a career or relationship, insecurities or because of any abuse, but because this person misses someone that they care about. I don't know what to do, I'm scared.

How old is this person? a minor or adult?

Sixteen years old

Tell her parents or a trusted teacher. Tell an adult who will help. Selfharm is no solution -- and she needs counseling to find out what better solutions there are.

His parents do not know but do not seem like people who would take him seriously if he told them which is making him worse, but I will still try and tell them, I suggested counselling but he said he would be scared to do that, I told him the scars and regret is not worth it but he said that they wouldn't be anything conpared to any psychological scars he now has.

Is school in session yet? Go with him to the school counselor. (Counseling is actually kinda cool.)

No, and he's going to a new school in September so I will go then.

Can you be there for him until then?

Yes, I always have been and always will be.

He hit the nail on the head there. There are many reasons for self-harm and to the mentally healthy we can't understand why. The most common is depression and feeling isolated. A lot of people who cut feeling so emotionally overwhelmed that they're numb and feel nothing at all. The pain from the cut makes them feel something. Reminds them that they're still alive. The exact reason is an individual as they are.

You can be there for him. Be his sounding board. Be his friend. Around where I am, Alberta, there is something called the kids help phone. It is an anonymous 800 number where kids/teens can call just to talk to someone. It is a lot easier to talk to someone you'll never see again and won't judge you for what you're saying. This is something he should explore. Show him that he's not alone, his problems aren't unique to him, people do understand and have been in situations like that before.

You're a good friend. Just bee there for him.

May I also chime in with self harm is a coping mechanism. He may have no other way to cope. It is neither bad or good it is still a coping mehcanism. There are of course healthier ways to cope but if that is all you have that is all you have. What it does is help lessen the stress levels.
What can you do:
1. Support him as much as you are comfortable doing. You also need to look out for yourself
2. Tell him you are there if he needs to talk but don't badger or demand to know if he has self injured
3. Talk to him about options. Help lines, school counsellor, parents, teachers. You will also have to respect his decision if he does not want to go. Let me explain if you force him into it he will probably lie to the people trying to help and hide it better. I myself have fooled many a therapist and psych doc as you learn what to tell them.
4. I don't have a link but there is a great site for self harmers and family and friends. It is called Body Under Siege or BUS for short. That site helped me out lots