What should I tell my family if my health certificate fails?

If the medical examination fails, you can tell your family directly, so don't worry too much. It depends on what the unqualified items are. If they can be changed, you can choose not to tell your family and do it yourself. But if it is serious, you should confess to your family, because they will care about you and love you very much, so you don't need to think too much.