What are some common reasons for PHP pages to have loading issues, especially when dealing with large amounts of data?

Common reasons for PHP pages to have loading issues when dealing with large amounts of data include inefficient database queries, lack of proper indexing, and excessive looping or recursion. To solve these issues, optimize your database queries, ensure proper indexing on columns frequently used in queries, and limit the amount of data retrieved at once by using pagination or limiting results.

// Example of optimizing database query and limiting results
$query = "SELECT * FROM table WHERE condition LIMIT 10";
$result = mysqli_query($connection, $query);
while ($row = mysqli_fetch_assoc($result)) {
    // Process data here
}