A Hospital Information System (HIS) is a software application that manages the administrative, financial, and clinical aspects of a hospital or healthcare facility. It includes modules for patient registration, appointment scheduling, medical records management, billing and insurance, pharmacy management, and more.

To create a HIS with PHP, you will need to design the database schema, build the frontend user interface, and write the backend code to handle data storage and retrieval.

Here are the steps to create a basic HIS using PHP:

1. Design the database schema: Identify the entities and relationships in your application. Create tables for entities such as patients, doctors, appointments, medical records, billing, etc. Define the columns for each table and establish the relationships between them using foreign keys.

2. Create the frontend user interface: Use HTML, CSS, and JavaScript to design the user interface for your HIS. Create forms for patient registration, appointment scheduling, medical records entry, billing, etc. Use CSS to style the forms and layout the pages.

3. Set up the database connection: In your PHP code, establish a connection to the database using the appropriate credentials. You can use the mysqli or PDO extension to connect to the database and perform CRUD operations.

4. Implement registration and login functionality: Create PHP scripts to handle patient registration and login. Validate the user inputs and insert the data into the patients table. For login, check the entered credentials against the stored data to verify the user.

5. Build appointment scheduling functionality: Create PHP scripts to handle appointment scheduling. Allow patients to select a doctor, choose a date and time, and book an appointment. Update the appointments table with the new appointment details.

6. Implement medical records management: Create PHP scripts to handle the creation and updating of medical records. Allow doctors to add diagnoses, prescriptions, and test results to the patient’s medical record. Update the medical records table with the new data.

7. Implement billing and insurance functionality: Create PHP scripts to handle billing and insurance information. Allow users to enter billing details and verify insurance coverage. Update the billing and insurance tables with the new data.

8. Implement search and reporting functionality: Create PHP scripts to handle searching for patients, doctors, and appointments. Generate reports based on different criteria such as patient demographics, appointment history, etc.

9. Test and debug your HIS: Thoroughly test your application and fix any bugs or issues that arise. Make sure all the functionality is working as intended and the data is being stored and retrieved correctly.

10. Deploy the application: Once you are satisfied with your HIS, deploy it to a web server or hosting provider to make it accessible to users. Ensure that the server has the necessary dependencies installed (PHP, MySQL, etc.) and configure it accordingly.

Remember to follow best practices for security and data privacy when developing your HIS. Use proper input validation, session management, and encryption techniques to protect sensitive data.

Building a complete HIS is a complex task that requires a deep understanding of healthcare management systems and knowledge of PHP and database design. Consider partnering with experienced developers or healthcare IT consultants to ensure a successful implementation.