Answer:
Be kind about it and tell them that you are there for them.
Explanation: I have been in this situation and I understand how difficult it can be. What you need to do is to try and help them yourselves like possibly take away the object they use to self harm and talk to them. You don't have to say that you know but let them know you are there for them. Search for sign on whether it is getting better or worse. If it starts to get worse and out of your hands you need to say something to a trusted adult. Start monitoring this person and do anything and everything you can to help them. Search some information on google of signs if needed. Just know that it is okay to tell an adult if it gets out of hand. Some people feel like it is like betraying there friend, but it is not. You are trying to help them from something potentially life threatening. Which brings me to tell you make sure they aren't thinking of killing themselves and try to find the source of why they are cutting themselves. It might not be as serious as you think so don't jump to conclusions. But i'm just a passionate middle schooler so you shouldn't take everything to heart. If this isn't enough information for you or you have a question you can ask.
