PHP How to fix Notice: Undefined variable:

code:

Function ShowDataPatient($idURL)
{
    $query =" select * from cmu_list_insurance,cmu_home,cmu_patient where cmu_home.home_id = (select home_id from cmu_patient where patient_hn like '%$idURL%')
                     AND cmu_patient.patient_hn like '%$idURL%'
                     AND cmu_list_insurance.patient_id like (select patient_id from cmu_patient where patient_hn like '%$idURL%') ";


    $result = pg_query($query) or die('Query failed: ' . pg_last_error());

    while ($row = pg_fetch_array($result))
    {
        $hn = $row["patient_hn"];
        $pid = $row["patient_id"];
        $datereg = $row["patient_date_register"];
        $prefix = $row["patient_prefix"];
        $fname = $row["patient_fname"];

        $lname = $row["patient_lname"];
        $age = $row["patient_age"];
        $sex = $row["patient_sex"];
    }          
    return array($hn,$pid,$datereg,$prefix,$fname,$lname,$age,$sex);
}

Error :

Notice: Undefined variable: hn in C:\xampp\htdocs\...  
Notice: Undefined variable: pid in C:\xampp\htdocs\... 
Notice: Undefined variable: datereg in C:\xampp\htdocs\...    
Notice: Undefined variable: prefix in C:\xampp\htdocs\...    
Notice: Undefined variable: fname in C:\xampp\htdocs\...    
Notice: Undefined variable: lname in C:\xampp\htdocs\...    
Notice: Undefined variable: age in C:\xampp\htdocs\...    
Notice: Undefined variable: sex in C:\xampp\htdocs\...

how to fix that?