Check Checkboxes according to the data from the database

I have a form in my website that I want to update the information of the user (Edit Profile) and some of the informations of the user has to do with the diseases that might a user has. I have checkboxes in order to select any disease but how I can have already checked checkboxes according to the data from my database table. The code for the checkboxes is the below...

<label id="Disease">Your Disease(s):</label><br />
    <!--emfanizei tis epiloges gia ta diseases me basi auta p exoume sti basi mas -->
    <?php
  $sql = "SELECT name FROM disease";
  $query_resource = mysql_query($sql);
  while( $name = mysql_fetch_assoc($query_resource) ):
?>
    <span><?php echo $name['name']; ?></span>
    <input type="checkbox" name="disease[]" value="<?php echo $name['name']; ?>" /><br />

<?php endwhile; ?>

My database table is named as patient and look likes this

And my checkboxes look like this...

My update code ...

if(isset($_POST['username'])){

            $fname = mysql_real_escape_string($_POST["fname"]);
            $lname = mysql_real_escape_string($_POST["lname"]);            
            $email = mysql_real_escape_string($_POST["email"]);
            $password = mysql_real_escape_string($_POST["password"]);
            $age = ($_POST["age"]);
            $disease = implode(",",$_POST["disease"]);         

            $query="UPDATE patient
                    SET fname = '$fname', lname = '$lname', email = '$email', password = '$password', age='$age', disease='$disease'
                    WHERE username='$username'";

            mysql_query($query)or die(mysql_error());
            if(mysql_affected_rows()>=0){
                echo "<p>($username) Record Updated<p>";
            }else{
                echo "<p>($username) Not Updated<p>";
            }
        }