How to determine if a binary tree is height-balanced

#include<cstdlib>
#include<iostream>
using namespace std;
class Node{
  public:
      int data;
      Node *left,*right;
      Node(int key){
        data=key;
        left=right=NULL;
        }
  };

  int Height(Node* root){
    if(root==NULL)
      return 0;
    return max(Height(root->left),Height(root->right))+1;
    }

 int CheckHeightBalanced(Node *root){
  if(root==NULL)
     return 1;
  int height_diffrence=abs(Height(root->left)-Height(root->right));
 return (CheckHeightBalanced(root->left)&&CheckHeightBalanced(root->right)&&height_diffrence<=1);
  }

void Insert(Node **root_ref,int key){
  if(*root_ref==NULL){
    *root_ref=new Node(key);
    return;
    }
  if((*root_ref)->data<key)
    Insert(&((*root_ref)->right),key);
  else
     if((*root_ref)->data>key)
       Insert(&((*root_ref)->left),key);
  }

int main(){
 Node *root=NULL;
 Insert(&root,5);
 Insert(&root,7);
 Insert(&root,6);
 Insert(&root,2);
 Insert(&root,8);
 if(CheckHeightBalanced(root))
   cout<<"yes";
 else
   cout<<"no";
 }