Though self-harm is rarely a failed suicide attempt, it is a sign that the person doing it is coping with very difficult feelings, and probably needs some help. Self-injury can also lead to infection, permanent damage and even accidental death. It is therefore important to seek professional advice if your child is self-harming.
Start by going to see your GP. You can see the GP yourself if your child does not want to go. You should also ask your GP what to do if your child's cuts get infected. Your GP may refer you and your child to Child and Adolescent Mental Health Services (CAMHS).
If you are worried your child is putting their life at risk by self-harming, call 999 or take them to A&E if possible.