Identify which fields are changed on the record

Hi to Salesforce ,

Here is the small snippet that can help to identify which field is changed on the record using sobject methods.

   list<string> lstAPIfields = new list<string>();

            Map <String, Schema.SObjectType> schemaMap = Schema.getGlobalDescribe();

            Map <String, Schema.SObjectField> fieldMap = schemaMap.get('Lead').getDescribe().fields.getMap();

            for(Schema.SObjectField sfield : fieldMap.Values()){

                 schema.describefieldresult dfield = sfield.getDescribe();

                 if(dfield.isUpdateable()){

                    lstAPIfields.add(dfield.getname());

                 }

            }

            system.debug('****lstAPIfields'+lstAPIfields);

            for(lead objlead:lstNew){

                sobject sobjNew = objlead;

                sobject sobjOld = mpOld.get(objlead.id);

                for(string strfield:lstAPIfields){

                    if(sobjNew.get(strfield)!=sobjOld.get(strfield)){

                        system.debug('***********FIELD MODIFIED'+strfield);

                    }

                }

            }

Thank you.