<select name= "indication_name" id= "update_indication_id" class="form-control" required>
  <?php
      $sql = "SELECT id,description From indications";
      $result=mysqli_query($con,$sql);
      while($row=mysqli_fetch_array($result)){
          echo "<option selected='selected'>" . $row['id']." - ". $row['description'];
      }

   ?>
</select>

<select name= "indication_name" id= "update_indication_id" class="form-control" required>
  <?php
      $sql = "SELECT id,description From indications";
      $result=mysqli_query($con,$sql);
      while($row=mysqli_fetch_array($result))
          echo "<option value='" . $row['id'] . "'>" . $row['description'] . "</option>";
   ?>
</select>

<select name= "indication_name" id= "update_indication_id" class="form-control" required>
  <option selected="selected" value="">-- Select an option --</option>
  <?php
      $sql = "SELECT id,description From indications";
      $result=mysqli_query($con,$sql);
      while($row=mysqli_fetch_array($result))
          echo "<option value='" . $row['id'] . "'>" . $row['description'] . "</option>";
   ?>
</select>

<?php
$server="localhost";
$username="root";
$password="";
$link=@mysql_connect($server, $username, $password) or die ("Cannot connect to mysql server: ".@mysql_error());
$dbname = 'database_name';
@mysql_select_db($dbname, $link) or die ("Cannot connect to database: ".@mysql_error());

$query="SELECT id,description from indications";
$result = @mysql_query ($query);
echo "<select name=indication_name value=' '>";
while($drop=@mysql_fetch_array($result)){
echo "<option value=$drop[id]>$drop[description]</option>";
}
echo "</select>";
?>